24.An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What is the width of the 90% confidence interval?

Select one:

a.$465.28

b.$728.60

c.$232.64

d.$364.30

25.LetXrepresent the number of children in an Indian household. The probability distribution ofXis as follows:

x

1

2

3

4

5

p(x)

0.25

0.33

0.17

0.15

0.10

What is the probability that a randomly selected Indian household will have fewer than 4 children?

Select one:

a.0.75

b.0.15

c.0.17

d.0.42

26.Which of the following about the binomial distribution is NOT a true statement?

Select one:

a.Each outcome is independent of the other

b.The random variable of interest is continuous

c.The probability of success must be constant from trial to trial

d.Each outcome may be classified as either "success" or "failure"

27.The width of a confidence interval estimate for a proportion will be:

Select one:

a.narrower when the sample proportion is 0.50 than when the sample proportion is 0.20.

b.narrower for 99% confidence than for 95% confidence.

c.wider for a sample size of 100 than for a sample size of 50.

d.narrower for 90% confidence than for 95% confidence.