Practice Test


Q1) The distribution of total probability over different mass points or class intervals is called - Show Answer


Q2) Probability distribution is defined only for - Show Answer


Q3) Theoretical distribution possess all the characteristics of an Show Answer


Q4) __________ is a Discrete Probability Distribution Show Answer


Q5) ___________is a Continuous Probability Distribution Show Answer


Q6) Theoretical distributions are used to make future projections. Show Answer


Q7) Trial is an attempt to produce particular outcome which is Show Answer


Q8) Binomial distribution is a ______________ distribution. Show Answer


Q9) Binomial distribution is Show Answer


Q10) Characteristics of Bernoulli trial are Show Answer


Q11) Mean = Variance this is true for Show Answer


Q12) In case of Bernoulli trial the outcomes of the trials are Show Answer


Q13) When p=0.5 the maximum value of variance is Show Answer


Q14) In B(n,p) variance will always be ____________ mean. Show Answer


Q15) If for a Binomial distribution (n+1)p is a non - integer then mode of that distribution is Show Answer


Q16) Binomial distribution is applicable only when Show Answer


Q17) Poisson distribution was introduced by Show Answer


Q18) Poisson distribution is known as _____________ distribution. Show Answer


Q19) Poisson distribution is Show Answer


Q20) In Poisson distribution if "m" is non - integer then mode = Show Answer


Q21) In poisson distribution the number of trials tends to infinity. Show Answer


Q22) In Binomial and Poisson Distribution, mean = np Show Answer


Q23) The condition not satisfied by a random experiment of poisson distribution are Show Answer


Q24) In the x ~ P(m) the value probability of success (p) is very Show Answer


Q25) In Poisson distribution if m is an integer mode is Show Answer


Q26) For finding distribution of the number of spade cards when a card is drawn from a pace of 52 cards for 5 times the method is Show Answer


Q27) The following are continuous probability distributions : Normal, Chi-square, t-distribution and F-distribution Show Answer


Q28) Normal distribution was mainly derived by Show Answer


Q29) Normal distribution is Show Answer


Q30) Binomial distribution is symmetrical when Show Answer


Q31) Normal curve is a symmetrical curve Show Answer


Q32) Normal curve is bell shaped and has multi peaks Show Answer


Q33) Total area of the normal curve is taken as Show Answer


Q34) Total area of any probability curve is taken as Show Answer


Q35) Normal distribution is Show Answer


Q36) For an asymmetrical distribution Show Answer


Q37) For an symmetrical distribution Show Answer


Q38) If the distribution is asymmetrical then the skewness is zero Show Answer


Q39) If the distribution is symmetrical then the skewness is zero Show Answer


Q40) Number of points of inflexion a normal curve has _________ Show Answer


Q41) For Normal distribution P(0 < z < 1) is Show Answer


Q42) For Normal distribution P(-3 < z < 3) is Show Answer


Q43) The point at which normal curve changes its curvature from convex to concave is called Show Answer


Q44) For a standard normal distribution the points of inflexion are at Show Answer


Q45) When p=0.8 the Binomial distribution is Show Answer


Q46) When p=0.25 the Binomial distribution is Skewed towards Show Answer


Q47) The number of observations that can be chosen without any restriction is called Show Answer


Q48) Chi - square distribution is used for Show Answer


Q49) Chi - square distribution is always Show Answer


Q50) Mean of t-distribution is Show Answer


Q51) t-distribution is ____________ about t=0 Show Answer


Q52) If the probability that any person 40 years old will be dead within a year is p=0.01. Find the probability that out of a group of 7 such persons, none will die within one year. Show Answer


Q53) If the probability that any person 40 years old will be dead within a year is p=0.01. Find the probability that out of a group of 7 persons; exactly one will die within one year. Show Answer


Q54) If the probability that any person 40 years old will be dead within a year is p=0.01. Find the probability that out of a group of 7 persons; not more than one will die within one year. Show Answer


Q55) If the probability that any person 40 years old will be dead within a year is p=0.01. Find the probability that out of a group of 7 persons; more than one will die within one year. Show Answer


Q56) If the probability that any person 40 years old will be dead within a year is p=0.01. Find the probability that out of a group of 7 persons; at least one will die within one year. Show Answer


Q57) Out of 1000 families of 3 childern each, how many families would you expect to have 2 boys and girl are equally likely? Show Answer


Q58) If hens of a certain breed lay eggs on 5 days a week on an average, find how many days during a season of 100 days, a poultry keeper with 5 hens of hens of their breed will expect to receive at least 4 eggs? Show Answer


Q59) It is observed that 4 % of the students of a certain class wear glasses. If 5 students of this class are selected at random, what is the chance that among them, at least one wear glasses? Show Answer


Q60) The incidence of occupational disease in an industry is such that the workers have a 20 % chance of suffering from it. What is the probability that out of six workers 4 or more will catch the disease? Show Answer


Q61) It is observed that one out of four persons requires on an average medical help. Find the probability that at least one person out of three requires medical help. Show Answer


Q62) It is observed that one out of four persons requires on an average medical help. Find the probability that only one person out of three requires medical help. Show Answer


Q63) In a large consignment of bolts, 10 % are defective. In a sample of 4 bolts drawn at random from the consignment, find the probability that the sample contains no defective bolts. Show Answer


Q64) In a large consignment of bolts, 10 % are defective. In a sample of 4 bolts drawn at random from the consignment, find the probability that the sample contains at least one defective bolt. Show Answer


Q65) If the probability of a defective bolt is 1/10. find the following for the Binomial distribution of defective bolts in a total of 400 : (i) mean, (ii) S.D Show Answer


Q66) In a Binomial distribution with 6 independent trails, the probability of 3 and 4 successes are found to be 0.2457 and 0.0819 respectively. Find the parameter p of the Binomial Show Answer


Q67) If we take 1280 sets each of 10 tosses of a coin, in how many sets, should we expect to get 7 heads and 3 tails? Show Answer


Q68) The probability that a student is not a swimmer is 20 %. Out of 5 students selected. Find the probability that (a) 4 are swimmers. Show Answer


Q69) The probability that a student is not a swimmer is 20 %. Out of 5 students selected. Find the probability that at least 4 are swimmers. Show Answer


Q70) Take 100 sets of 10 tosses of an unbiased coin. In how many tosses do you expect to get 8 or more heads? Show Answer


Q71) Three fair coins are tossed 3000 times. Find the frequencies of the distribution of heads and tails and tabulate the result. Show Answer


Q72) Three fair coins are tossed 3000 times. Find mean and S.D. of the distribution. Show Answer


Q73) A box contains 100 bolts of which 10 are defective. Find the probability that a bolit chosen at random is not defective. Show Answer


Q74) Examine the validity of the following statement: mean of a binomial distribution is 10 and standard deviation is 4. Show Answer


Q75) Suppose that sizes of hats are approximately normally distribution with mean of 18.5 cm and a s.d. of 2.5 cm. how many hats in the total of 2000 will have sizes between 18 cms and 20 cms? (Area between z=0 and z=0.6 is 0.2257 and the area between z=0 and z=0.2 is 0.793 where z is the standard normal variate Show Answer


Q76) Suppose that sizes of hats are approximately normally distribution with mean of 18.5 cm and a s.d. of 2.5 cm. how many hats in the total of 2000 will have sizes more than 20 cms? (Area between z=0 and z=0.6 is 0.2257 and the area between z=0 and z=0.2 is 0.0793 where is the standard normal variate) Show Answer


Q77) Earnings of 10000 persons conform to the normal curve with mean of Rs.750 p.m. and s.d. of Rs.50. finds the number of persons with income exceeding Rs. 670? (Given that area between z= 0 and z=1.6 is 0.4452; area between z= 0 and z=0.6 is 0.2257; area between z=0 and z=2.33 is 0.49) Show Answer


Q78) Earnings of 10000 persons conform to the normal curve with mean of Rs.750 p.m. and s.d. of Rs.50. finds the number of persons with income not less than Rs.720. (Given that area between z= 0 and z=1.6 is 0.4452; area between z= 0 and z=0.6 is 0.2257; area between z= 0 and z=2.33 is 0.49) Show Answer


Q79) Earnings of 10000 persons conform to the normal curve with mean of Rs.750 p.m. and s.d. of Rs.50. finds the number of persons with income what is the highest income of the poorest 100 persons. (Given that area between - z=0 and z=1.6 is 0.4452; area between z=0 and z=0.6 is 0.2257; area between z=0 and z=2.33 is 0.49) Show Answer


Q80) The weights of 4000 students are found to be normally distributed with mean 50 kgs. And S.D. 5 kgs. Find the number of students with weights less than 45 kgs. (You are given the area under z=0 to z=1 is 0.3413 and z=0 and z=2 is 0.4772) Show Answer


Q81) The weights of 4000 students are found to be normally distributed with mean 50 kgs. And S.D. 5 kgs. Find the number of students with weights between 45 and 60 kg. (You are given the area under z= 0 to z= 1 is 0.3413 and z=0 and z=2 is 0.4772) Show Answer


Q82) A census of rentals for apartments in a city follows a normal distribution with mean Rs.800 and s.d. Rs.100. what is the probability that an apartment selected at random will have its rent between Rs.800 and Rs.1000? (Area between t=0 and t=2 is 0.4772; t=0 and t=1 is 0.3413; t=0 and t=1.5 is 0.4332) Show Answer


Q83) A census of rentals for apartments in a city follows a normal distribution with mean Rs.800 and s.d. Rs.100. what percentage of apartment will have their rent between Rs.600 and Rs.900? (Area between t=0 and t=2 is 0.4772; t=0 and t=1 is 0.3413; t=0 and t=1.5 is 0.4332) Show Answer


Q84) A census of rentals for apartments in a city follows a normal distribution with mean Rs.800 and s.d. Rs.100. what percentage of apartment will have their rent below Rs.650? (Area between t=0 and t=2 is 0.4772; t=0 and t=1 is 0.3413; t=0 and t=1.5 is 0.4332) Show Answer


Q85) The I.Q. scores of 1500 applicants for admission to a tuition-free graduate school are normally distributed with a mean of 125 and a standard deviation of 10. What percentage of applicants will have their I.Q. between 125 and 135? Show Answer


Q86) The I.Q. scores of 1500 applicants for admission to a tuition-free graduate school are normally distributed with a mean of 125 and a standard deviation of 10. What are the limits of I.Q. for the middle 50 per cent applicants? Show Answer


Q87) Average daily sales for a shop follow a normal distribution. It is given that the probability that the average daliy sale is less than Rs.124 is 0.0228 and the probability that it exceeds 331 is 0.1587. find the mean and the standard deviation of the distribution. (Area between t= 0 and t=1 is 0.3413. Area between t=0 and t=2 is 0.4772) Show Answer


Q88) The heights of 1000 cakes baked with a certain mix have a normal distribution with mean of 5.75 cms. And a student's deviations of 0.75 cm. Find the maximum heights of the flattest 200 cakes. (For a standard normal variate t, the area between t=-1 and t=1 is 0.6826; the area between t=0 and t=0.67 is 0.2486 and the area between t=0 and t=0.84 is 0.3000) Show Answer


Q89) The heights of 1000 cakes baked with a certain mix have a normal distribution with mean of 5.75 cms. And a student's deviations of 0.75 cm. Find the number of cakes having heights between 5 cms and 6.25 cms. (For a standard normal variate t, the area between t=-1 and t=1 is 0.6826; the area between t=0 and t=0.67 is 0.2486 and the area between t=0 and t=0.84 is 0.3000) Show Answer


Q90) The income of a group of 10000 persons were found to be normally distribution with mean Rs.500.00 and standard deviation Rs.60. Find the number of persons having incomes between Rs.400 and Rs.500. (For a standard normal variate t , the area under the curve between t=0 and t=0.5 is 0.19146, the area between t=0 and t=1.645 is 0.45000 and the area between t=0 and t=2 is 0.47725, Area between t=0 and t=1.67 is 0.4525.) Show Answer


Q91) The incomes of a group of 10000 persons were found to be normally distribution with mean Rs.500.00 and standard deviation Rs.60. Find the lowest income of the richest 500. (For a standard normal variate , the area under the curve between t=0 and t=0.5 is 0.19146, the area between t=0 and t=1.645 is 0.45000 and the area between t=0 and t=2 is 0.47725, Area between t=0 and t=1.67 is 0.4525.) Show Answer


Q92) What are the characteristics of a normal curve? If the heights of 1000 soldiers in a regiment are distributed normally with a mean of 172 cms and a standard deviation 5 cms how many soldiers have heights greater than 180 cms? (The area of a standard normal variate t between t=-1.6 and t=1.6 is 0.8904) Show Answer


Q93) The heights of 1000 soldiers in a regiment are distributed normally with a mean of 175 cms and s.d. 5 cms. How many soldiers are expected to have a height of 180 cms or more? Show Answer


Q94) The heights of 1000 soldiers in a regiment are distributed normally with a mean of 175 cms and s.d. 5 cms. How many would be expected to be shorter than 170 cms? Show Answer


Q95) The heights of 1000 soldiers in a regiment are distributed normally with a mean of 175 cms and s.d. 5 cms. How many will have their height between 165 cms and 185 cms? Show Answer


Q96) Assume the mean height of soldiers to be 68.22 inches with a variance of 10.8 inches. How many soldiers in a regiment of 1000 would you expect to be over six feet tall? (Area under normal curve between t=0 and t=1.15 is 0.3749). Show Answer


Q97) A hundred squash balls are tested by dropping from a height of 100 inches and measuring the height of bounce. A ball is "fast" if it rises above 32 inches. The average height of bounce was 30 inches and the standard deviation was 3/4 inches. What is the chance of getting a "fast" standard ball? (Area under normal curve between z= 0 and z=2.67 is 0.4962) Show Answer


Q98) Suppose that X is a continuous variable with a normal distribution and has a mean of 10 and standard deviation equal to 2. What is the probability that the value of X selected at random lies between 9 and 12? (Area under normal curve between z=0 and z=1 is 0.3413 and z=0 and z=0.5 is 0.1915) Show Answer


Q99) In a sample of 1000 items, the mean weight and standard deviation are 50 and 10 kgs respectively. Assuming the distribution the distribution to be normal, find the number of items weighing between 40 and 70 kgs. Show Answer


Q100) For a normal distribution with mean 120 and S.D. 40, what is the probability of P(x<=(150/x)>120)? (Area under normal curve between z=0 and z=0.75 is 0.3734) Show Answer


Q101) For finding distribution of the number of radio-active elements per minute in a fusion process the method used is Show Answer


Q102) Binomial can be approximated by poisson distribution than Show Answer


Q103) For a normal distribution the p.d.f is defined as Show Answer


Q104) For a normal distribution the following is incorrect: Show Answer


Q105) For Poisson distribution S.D is ___________ Show Answer


Q106) Mean of a chi-square distribution is Show Answer


Q107) S.D. of a chi - square distribution is Show Answer


Q108) S.D. of t-distribution is ______________, when n >2. Show Answer


Q109) Mean of F-distribution is Show Answer


Q110) If the probability that any person 40 years old will be dead within a year is p = 0.01. Find the probability that out of a group of 7 persons; all of them will be dead within year. Show Answer


Q111) A theoretical probability distribution Show Answer


Q112) Theoretical distribution is a Show Answer


Q113) Probability distribution may be Show Answer


Q114) Probability function is known as Show Answer


Q115) A trial is an attempt to Show Answer


Q116) The no. of points obtained in a single throw of an unbiased dice follow: Show Answer


Q117) The occurrence of point in a single throw of a fair die follows the frequency distribution Show Answer


Q118) In uniform distribution random variable x assumes n values with Show Answer


Q119) In a discrete random variable x follows uniform distribution and assumes only the values 8, 9, 11, 15, 18, 20. Then P(x = 9) is Show Answer


Q120) In a discrete random variable x follows uniform distribution and assumes only the values 8, 9, 11, 15, 18, 20. Then P(x = 12) is Show Answer


Q121) In a discrete random variable x follows uniform distribution and assumes only the values 8, 9, 11, 15, 18, 20. Then P(x < 15) is Show Answer


Q122) A Random variables X follows uniform distribution in the interval [-3, 7]. Then the mean of distribution is Show Answer


Q123) When there are a fixed number of repeated trial of any experiments under identical conditions for which only one of two mutually exclusive outcomes, success or failure can result in each trial then Show Answer


Q124) The important characteristic(s) of Bernoulli trials Show Answer


Q125) The method usually applied for fitting a binomial distribution is known as Show Answer


Q126) The result of ODI matches between India and Pakistan follows Show Answer


Q127) _____ is / are Bi-parametric distribution(s). Show Answer


Q128) A Binomial distribution is _____ . The parameter(s) are Show Answer


Q129) The probability mass function of binomial distribution is given by Show Answer


Q130) For n independent trials in Binomial distribution the sum of the powers of p and q is always _____, whatever be the no. of success. Show Answer


Q131) In Binomial distribution 'p' denotes Probability of Show Answer


Q132) In Binomial distribution 'n' means Show Answer


Q133) Mean of Binomial distribution is Show Answer


Q134) Standard deviation of binomial distribution is Show Answer


Q135) Variance of Binomial distribution is Show Answer


Q136) The variance of a binomial distribution with parameters n and p is Show Answer


Q137) In Binomial distribution Show Answer


Q138) Binomial distribution is symmetrical is Show Answer


Q139) For a binomial distribution, mean and mode Show Answer


Q140) If x is a binomial variable with parameters n and p, then x can assume Show Answer


Q141) For a binomial distribution, there may be Show Answer


Q142) The maximum value of the variance of a binomial distribution with parameters n & p is Show Answer


Q143) When 'p' = 0.5, the binomial distribution is Show Answer


Q144) When 'p' is large than 0.5, the binomial distribution is Show Answer


Q145) When p = 0.1 the binomial distribution is skewed to the Show Answer


Q146) When a coin is tossed 10 times then the Probability Distribution of the number of Heads forms a Show Answer


Q147) If in Binomial distribution np = 9 and npq = 2.25 then p and n are equal to is equal to Show Answer


Q148) An unbiased dice is tossed 500 times. The mean of the no. of 'Sixes' in these 500 tosses is Show Answer


Q149) An unbiased dice is tossed 500 times. The Standard deviation of the no. of 'sixes' in these 500 tossed is Show Answer


Q150) In Binomial distribution if mean = 20, SD = 4 then ? is equal to Show Answer


Q151) In Binomial distribution, if n = 4 and p = 1/3 then the value of variance is Show Answer


Q152) In Binomial distribution if mean = 20, SD = 4 then q is equal to Show Answer


Q153) What is the no. of trials of a binomial distribution having mean and SD as 3 and 1.5 respectively? Show Answer


Q154) A random variable x follows Binomial distribution with E(X) = 2 and V(X) = 1, 2. Then the value of n is Show Answer


Q155) A random variable x follows Binomial distribution with mean 2 and variance 1.6. then the value of p is Show Answer


Q156) X is binomial random variable. In a game of 4 trials P(x = 2) = 8/27, then the variance is Show Answer


Q157) If in a binomial distribution n = 4, P(X = 0) = 16/81, then P(X = 4) is Show Answer


Q158) X is a binomial variable with n = 20. What is the mean of X if it is known that x is symmetric? Show Answer


Q159) What is the standard deviation of the number of recoveries among 48 patients when the probability of recovering is 0.75? Show Answer


Q160) If the overall percentage of success in an exam is 60, what is the probability that out of a group of 4 students, atleast one has passed? Show Answer


Q161) What is the probability of making 3 correct guesses in 5 True-False answer type questions? Show Answer


Q162) Out of 128 families with 4 children each, how many are expected to have atleast one boy and one girl? Show Answer


Q163) In 10 independent rollings of a biased dice, the probability that an even number will appear 5 times is twice the probability that an even number will appear 4 times. What is the probability that an even number will appear twice when the die is rolled 8 times? Show Answer


Q164) If it is known that the probability of a missile hitting a target is 1/8, what is the probability that out of 10 missiles fired, atleast 2 will hit the target? Show Answer


Q165) What is the probability of getting 3 heads if 6 unbiased coins are tossed simultaneously? Show Answer


Q166) A man tosses a fair coin 10 times, the probability that he has heads on the first five tosses is Show Answer


Q167) What is the probability of having atleast one 'six' from 3 throws of a perfect die? Show Answer


Q168) A die is thrown 100 times. If getting an even number is considered a success, then the variance of the number of successes is Show Answer


Q169) A die was thrown 400 times and 'six' resulted 80 times then observed value of proportion is Show Answer


Q170) A coin is tossed 10 times. Assuming the coin to be unbiased, what is the probability of getting at least 4 heads? Show Answer


Q171) A coin is tossed 8 times. Assuming the coin to be unbiased, what is the probability of getting at most 3 heads? Show Answer


Q172) 6 coins are tossed 512 times. Also, compute the mean and SD of the number of heads. Show Answer


Q173) If 15 dates are selected at random, what is the probability of getting two Sundays? Show Answer


Q174) Find the probability of success for the binomial distribution satisfying the following relation, 4 P(x = 4) = P(x = 2) and having the other parameter as six. Show Answer


Q175) Find the binomial distribution for which mean and standard deviation are 6 and 2 respectlvely. Show Answer


Q176) An experiment succeeds thrice as after it fails. If the experiment is repeated 5 times, what is the probability of having no success at all? Show Answer


Q177) If x is a binomial variate with parameter 15 and 1/3, what is the value of mode of the distribution? Show Answer


Q178) X is a binomial variable such that 2 P(X = 2) = P(X = 3) and mean of X is known to be 10/3. What would be the probability that X assumes at most the value 2? Show Answer


Q179) Assuming that one-third of the population are tea drinkers and each of 1000 enumerators takes a sample of 8 individuals to find out whether they are tea drinkers or not, how many enumerators are expected to report that five or more people are tea drinkers? Show Answer


Q180) If a random variable X follows binomial distribution with mean as 5 and satisfying the condition 10 P(X = 0) = P(X = 1), what is the value of P(X > 0)? Show Answer


Q181) For a binominal distribution, the parameters are 15 and 1/3 Find mode: Show Answer


Q182) Standard Deviation of binominal distribution is Show Answer


Q183) In the Binomial distribution the parameters are n and p, then X assumes value: Show Answer


Q184) For a Binomial distribution mean is 4 and variance is 3 then, 3rd central moment is Show Answer


Q185) _____ distribution is a limiting case of Binomial distribution. Show Answer


Q186) If x ~ B (5, p) and p (x = 2) = 0.4362 and p (x = 3) = 0.2181, then p = Show Answer


Q187) A binomial distribution with parameters n and p can be approximated by a Poisson distribution with parameter m = np is Show Answer


Q188) When the no. of trials is large then Show Answer


Q189) Which one is uniparametric distribution? Show Answer


Q190) Poisson distribution is a _____ probability distribution. Show Answer


Q191) _____ distribution is sometimes known as the "distribution of rare events". Show Answer


Q192) For Poisson fitting to an observed frequency distribution, Show Answer


Q193) In a Poisson distribution, Show Answer


Q194) In Poisson distribution, np is Show Answer


Q195) In Poisson distribution Show Answer


Q196) Standard deviation of poisson distribution is Show Answer


Q197) Poisson distribution may be Show Answer


Q198) In Poisson distribution, probability of success is very close to Show Answer


Q199) Poisson distribution may be Show Answer


Q200) The Poisson distribution tends to be symmetrical if the mean value is Show Answer


Q201) No. of radio-active atoms decaying in a given interval of time is an example of Show Answer


Q202) Number of misprints per page of a thick book follows Show Answer


Q203) Poisson distribution approaches a Normal distribution as n Show Answer


Q204) The standard deviation of a Poisson variate is 1.732. What is the probability that the variable lies between -2.3 to 3.68? Show Answer


Q205) For a Poisson variate X, P(X = 1) = P(X = 2). What is the mean of X? Show Answer


Q206) Find the mean and standard deviation of x where x is a Poisson variate satisfying the condition P(x = 2) = P(x = 3). Show Answer


Q207) X is a Poisson variate satisfying the following relation: P (X = 2) ? 9 P(x = 4) + 90 P (X = 6). What is the standard deviation of X? Show Answer


Q208) If for a Poisson variable X, f(2) = 3 f(4), what is the variance of X? Show Answer


Q209) A random variable x follows Poisson distribution and its coefficient of variation is 50. What is the value of P (x > 1/x > 0)? Show Answer


Q210) If 1.5% of items produced by a manufacturing units are known to be defective, what is the probability that a sample of 200 items would contain no defective item? Show Answer


Q211) If 1% of an airline's flights suffer a minor equipment failure in an aircraft, what is the probability that there will be exactly two such failures in the next 100 such flights? Show Answer


Q212) If 2 per cent of electric bulbs manufactured by a company are known to be defectives, what is the probability that a sample of 150 electric bulbs taken from the production process of the company would contain exactly one defective bulb? Show Answer


Q213) If 2 per cent of electric bulbs manufactured by a company are known to be defectives, what is the probability that a sample of 150 electric bulbs taken from the production process of the company would contain more than two defective bulbs? Show Answer


Q214) Between 9 and 10 AM, the average number of phone calls per minute coming into the switchboard of the company is 4. Find the probability that during one particular minute there will be no phone calls? Show Answer


Q215) A renowned hospital usually admits 200 patients every day. 1% patients, on an average, require special room facilities. On one particular morning, it was found that only one special room is available. What is the probability that more than 3 patients would require special room facilities? Show Answer


Q216) The number of accidents in a year attributed to taxi drivers in a locality follows Poisson distribution with an average 2. Out of 500 taxi drivers of that area, what is the number of drivers with atleast 3 accidents in a year? Show Answer


Q217) In _____ distribution, Mean = Variance: Show Answer


Q218) Which of the following is false in case of Normal Distribution? Show Answer


Q219) In continuous probability distribution F(x) is called Show Answer


Q220) If neither p nor q is very small but n sufficiently large, the Binomial distribution is very closely approximated by _____ distribution. Show Answer


Q221) The most important continuous probability distribution is known as Show Answer


Q222) For continuous variates _____ distribution is used. Show Answer


Q223) Probability density function is associated with Show Answer


Q224) Probability density function is always Show Answer


Q225) In continuous cases probability of the entire space is Show Answer


Q226) In discrete cases the probability of the entire space is Show Answer


Q227) In Normal distribution the probability has the maximum value at the Show Answer


Q228) In Normal distribution, the probability decreases gradually on either side of the mean but never touches the axis. Show Answer


Q229) Whatever may be the parameter of distribution, it has same shape. Show Answer


Q230) In standard normal distribution Show Answer


Q231) Normal distribution mean, median and mode are Show Answer


Q232) The no. of methods for fitting the normal curve is _____ . They are _____. Show Answer


Q233) The normal curve is Show Answer


Q234) Area of the normal curve is Show Answer


Q235) The total area of the normal curve is Show Answer


Q236) The normal curve is Show Answer


Q237) The curve of _____ distribution has single peak. Show Answer


Q238) The curve of _____ distribution is unimodal and bell shaped with the highest point over the mean. Show Answer


Q239) The wage of workers of factory follow. Show Answer


Q240) In Normal distribution the quartiles are equidistant from Show Answer


Q241) Because of the symmetry of Normal distribution the median and the mode have the _____ value as that of the mean. Show Answer


Q242) For a standard normal distribution, the points of inflexion are given by Show Answer


Q243) In Normal distribution as the distance from the ------ increases, the curve comes closer and closer to the horizontal axis. Show Answer


Q244) The Second & third moments of observations {-6, -4, -2, 0, 2, 4, 6) are _____. Show Answer


Q245) In a Normal Distribution the relation between QD and SD is Show Answer


Q246) For a probability distribution,--------- is the expected value of x. Show Answer


Q247) For discrete random variable x, Expected value of x i.e. E(x) is defined as the sum of products of the different values and the corresponding probabilities. Show Answer


Q248) The probability density function of a normal variable x is given by Show Answer


Q249) The cumulative distribution function of a random variable X is given by Show Answer


Q250) The mean deviation about median of a standard normal variate is Show Answer


Q251) The quartile deviation of a normal distribution with mean 10 and SD 4 is Show Answer


Q252) In a sample of 500 workers of a factory, the mean wage and SD of wages are found to be Rs. 500 and Rs. 48 respectively. Find the number of workers having wages more than Rs. 600, less than Rs. 450, between Rs. 548 and Rs. 600. Show Answer


Q253) The distribution of wages of a group of workers is known to be normal with mean Rs. 500 and SD Rs. 100. If the wages of 100 workers in the group are less than Rs. 430, what is the total number of workers in the group? Show Answer


Q254) The mean of a normal distribution is 500 and 16 per cent of the values are greater than 600. What is the standard deviation of the distribution? Show Answer


Q255) x and y are independent normal variables with mean 100 and 80 respectively and standard deviation as 4 and 3 respectively. What is the standard deviation of (x + y)? Show Answer


Q256) A discrete random variable x follows uniform distribution and takes the values 6, 8, 10, 12, 18. The probability of P(x < 12) is Show Answer


Q257) If the mean deviation of a normal variable is 16, what is its quartile deviation? Show Answer


Q258) If the quartile deviation of a normal curve is 4.05, then its mean deviation is Show Answer


Q259) If the I quartile and the mean deviation about median of a normal distribution are 13.25 and 8 respectively, then the mode of the distribution is Show Answer


Q260) If X and Y are 2 independent normal variables with mean as 10 and 12 and SD as 3 and 4, then (X+Y) is normally distributed with Show Answer


Q261) In a business, it is assumed that the average daily sales expressed in rupees follows normal distribution. Find the coefficient of variation of sales given that the average daily sales is less than Rs.124 is 0.0287 and the probability that the average daily sales is more than Rs.270 is 0.4599. Show Answer


Q262) The salary of workers of a factory is known to follow normal distribution with an average salary of Rs.10,000 and standard deviation of salary as Rs.2,000. If 50 workers receive salary more than Rs. 14,000, then the total no. of workers in the factory is Show Answer


Q263) If the weekly wages of 5000 workers in a factory follows Normal Distribution with Mean and Std Deviation as Rs. 700 and Rs. 50 respectively. What is the expected number of workers with Wages between Rs. 660 and Rs. 720? Show Answer


Q264) In a Normal distribution mean = 2 and variance = 4 then, 4th central moment is Show Answer


Q265) X and Y are two independent Normal variables, then the distribution of X + Y is _____ Show Answer


Q266) An important continuous probability distribution Show Answer


Q267) _____ distribution is symmetrical around t = 0. Show Answer


Q268) As the degree of freedom increases, the _____ distribution approaches the Standard Normal distribution. Show Answer


Q269) _____ Distribution is asymptotic to the Horizontal axis. Show Answer


Q270) _____ distribution has a greater spread than Normal distribution curve. Show Answer


Q271) We use t-distributions when the sample size is Show Answer


Q272) We use t-distribution when samples are drawn from the _____ population. Show Answer


Q273) Which is most common diagrammatic representation for grouped frequency distribution. Show Answer


Q274) Wages paid to workers follows Show Answer


Q275) For an unknown parameter, how many interval estimate exists. Show Answer


Q276) t-test can be used only when the sample has been taken from _____ population. Show Answer


Q277) 4 coins were tossed 1600 times. What is the probability that all 4 coins do not turn head upward at a time? Show Answer


Q278) If mean and variance are 5 and 3 respectively then relation between p and q is: Show Answer


Q279) Area between=1.96 to +1.96 in normal distribution is: Show Answer


Q280) If the points of inflexion of a normal curve are 40 and 60 respectively, then its mean deviation is: Show Answer


Q281) For a Poisson distribution: Show Answer


Q282) Which of the following is uni-parametric distribution? Show Answer


Q283) If the probability of success in binomial distribution is less than one-half, then the binomial distribution__________. Show Answer


Q284) If we change the parameter of a _______ distribution the sharp of probability curve does not change. Show Answer


Q285) Which one of the following has Poisson distribution? Show Answer


Q286) The quartile deviation of a normal distribution with mean 10 and standard deviation 4 is______ Show Answer


Q287) If the parameter of Poisson distribution is m and (Mean +S.D)=6/25 then find m: Show Answer


Q288) A coin with probability for head as 1/5 is tossed 100 times. The standard deviation of the number of head 5 turned up is. Show Answer


Q289) For a normal distribution, the value of third moment about mean is. Show Answer


Q290) In Normal distribution, Mean, Median and Mode are: Show Answer


Q291) Which of the following diagram is the most appropriate to represents various heads in total cost? Show Answer


Q292) If x is binomial variate with P=1/3, for the experiment of 90 trials, then the standard deviation is equal to: Show Answer


Q293) The average number of advertisments per page appearing in a newspaper is 3. What is the probability that in a particular page zero number of advertisement are there? Show Answer


Q294) Four unbiased coins are tossed simultaneously. The expected number of head is: Show Answer


Q295) If, for a Poisson distribution random variable X, the probability for X taking value 2 is 3 times the probability for X taking value 4, then the variance of X is Show Answer


Q296) A renowned hospital usually admits 200 patients everyday. One percent patients, on an average, require special room facilities. On one particular morning, it was found that only one special room is available. What is the probability that more than 3 patients would require special room facilities? Show Answer


Q297) In a normal distribution, variance is 16 then the value of mean deviation is:
Show Answer


Q298) For a binomial distribution, there may be-

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Q299) If x is a Poisson variable and P (x = 1) = P (x = 2), then P (x = 4) is Show Answer


Q300) Skewness of Normal Distribution is:
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Q301) If a Poisson distribution is such that P(X=2)=P(X=3) then the variance of the distribution is :
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Q302) The Standard Deviation of Binomial distribution is: Show Answer


Q303) The speeds of a number of bikes follow a normal distribution model with a mean of 83 km/hr and a standard deviation of 9.4 km/hr.Find the probability that a bike picked at random is traveling at more than 95 km/hr.?[P(Z>1.28)=0.1003]
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Q304) The incident of skin diseases in a chemical plant occurs in such a way that its workers have 20% chance of suffering from it.What is the probability that 6 workers 4 or more will have skin diseases?
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Q305) Between 9 and 10am the average number of phone calls per minutes coming into the switch board of a company is 4.Find the probability that during one particular minute.There will be either two phone calls or no phone calls. Show Answer


Q306) If mean and variance of a random variable which follows the Binomial Distribution are 7 and 6 respectively, then the probability of success is:
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Q307) If six coins are tossed simultaneously.The probability of obtaining exactly two heads are. Show Answer


Q308) For a binomial distribution he mean and standard deviation are 10 and 3 respectively.Find the value of n.
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