Computer Oriented Statistical Techniques MCQs - 4 | 100+ MCQ Questions with Answers

76) The standard deviation of a sampling distribution of a statistic is often called its _____________

a) Standard Error
b) Probable Error
c) Maximum Error
d) Minimum Error

Ans: a

77) Ball bearings of a given brand weigh 0.50 g with a standard deviation of 0.02 g. What is the probability that two lots of 1000 ball bearings each will differ in weight by more than 2 g? Use ( probability(Z ≥ 2.23) = probability(Z ≤ - 2.23) = 0.4871)

a) 0.4871
b) 0.0258
c) 0.9742
d) 0.0129

Ans: b

78)

a) -0.7572
b) 0.7572
c) 0.2164
d) -0.2164

Ans: c

79)

a) -0.0226
b) -0.0113
c) 0
d) 0.0226

Ans: d

80) If it rains, an umbrella salesman can earn $30 per day. If it is fair, he can lose $6 per day. What is his expectation if the probability of rain is 0.3?

a) 4.8
b) 12
c) 18
d) 10.8

Ans: a

81) What is a fair price to pay to enter a game in which one can win $25 with probability 0.2 and $10 with probability 0.4?

a) 12.5
b) 9
c) 17.5
d) 10

Ans: b

82)

a) 18
b) 12
c) 7
d) 5

Ans: c

83) Find The probability that a man will be alive in 25 years is 3/5, and the probability that his wife will be alive in 25 years is 2/3. Find the probability that both will be alive.

a) 3/5
b) 2/3
c) 4/5
d) 2/5

Ans: d

84) A non-defective bolt will be found if out of 600 bolts already examined, 12 were defective. Probability of Non-defective Bolts is?

a) 588/600
b) 12/600
c) 612/600
d) 1

Ans: a

85) Probability of getting A 7 or 11 comes up in a single toss of a pair of fair dice

a) 3/9
b) 2/9
c) 1/9
d) 0

Ans: b

86) If the sampling distributions of two statistics have the same mean (or expectation), then the statistic with the smaller variance is called an _______________ of the mean.

a) Time Estimator
b) Distance Estimator
c) Efficient estimator
d) Data Estimator

Ans: c

87) An estimate of a population parameter given by a single number is called a ________________ of the parameter.

a) Interval estimate
b) Curve Estimate
c) Line Estimate
d) point estimate

Ans: d

88) An estimate of a population parameter given by two numbers between which the parameter may be considered to lie is called an ____________ of the parameter.

a) Interval estimate
b) Gap Estimate
c) Mean Estimate
d) Best Estimate

Ans: a

89)

a) Standard Error
b) probable error
c) Gap Error
d) Data Error

Ans: b

90)

a) 1.25
b) 6.23
c) 2.58
d) 4.22

Ans: c

91) A random sample of 50 mathematics grades out of a total of 200 showed a mean of 75 and a standard deviation of 10.What are the 95% confidence limits for estimates of the mean of the 200 grades?

a) 75 ± 1.2
b) 75 ± 1.8
c) 75 ± 2.1
d) 75 ± 2.4

Ans: d

92) A sample poll of 100 voters chosen at random from all voters in a given district indicated that 55% of them were in favour of a particular candidate. Find the 99.73 % confidence limits for the proportion of all the voters in favour of this candidate.

a) 0.55 ± 0.15
b) 0.55 ± 0.20
c) 0.55 ± 0.10
d) 0.55 ± 0.25

Ans: a

93) sample poll of voters chosen at random from all voters in a given district indicated that 55% of them were in favour of a particular candidate How large a sample of voters should we take in order to be 95% confident that the candidate will be elected?

a) 405
b) 385
c) 345
d) 425

Ans: b

94) The mean and standard deviation of the maximum loads supported by 60 cables are given by 11.09 tons and 0.73 ton, respectively. Find the 95% confidence limits for the mean of the maximum loads of all cables produced by the company.

a) 11.09 ± 0.24 tons
b) 11.09 ± 0.08 tons
c) 11.09 ± 0.18 tons
d) 11.09 ± 0.28 tons

Ans: c

95) The mean and standard deviation of the diameters of a sample of 250 rivet heads manufactured by a company are 0.72642 in and 0.00058 in, respectively. Find the 50% confidence limits for the mean diameters.

a) 0.72642 ± 0.25 in
b) 0.72642 ± 0.0025 in
c) 0.72642 ± 0.025 in
d) 0.72642 ± 0.000025 in

Ans: d)

96) If the standard deviation of the lifetimes of television tubes is estimated to be 100 h, how large a sample must we take in order to be 90% confident that the error in the estimated mean lifetime will not exceed 20 h?

a) At least 68
b) At least 24
c) At least 168
d) At least 101

Ans: a

97) An urn contains an unknown proportion of red and white marbles. A random sample of 60 marbles selected with replacement from the urn showed that 70% were red. Find the 99.73% confidence limits for the actual proportion of red marbles in the urn.

a) 0.70 ± 0.12
b) 0.70 ± 0.18
c) 0.70 ± 0.15
d) 0.70 ± 0.23

Ans: b

98) A poll of 1000 individuals over the age of 65 years was taken to determine the percent of the population in this age group who had an Internet connection. It was found that 387 of the 1000 had an internet connection. Using the equations in the book as well as statistical software, find a 97.5% confidence interval for p. (Use = 2.24)

a) (0.302, 0.472)
b) (0.332, 0.442)
c) (0.352, 0.422)
d) (0.322, 0.492)

Ans: c

99) Very often in practice we are called upon to make decisions about populations on the basis of sample information. Such decisions are called ___________.

a) Qualitative Decision
b) Quantitative Decision
c) Hypothetical Decision
d) Statistical decisions

Ans: d

100) In attempting to reach decisions, it is useful to make assumptions (or guesses) about the populations involved. Such assumptions, which may or may not be true, are called __________.