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Chapter 8: Q. T8.7 (page 549)

A 90%confidence interval for the mean 渭 of a population is computed from a random sample and is found to be90卤30. Which of the following could be the 95%confidence interval based on the same data?

a. 90卤21

b. 90卤30

c. 90卤39

d. 90卤70

e. Without knowing the sample size, any of the above answers could be the 95%confidence interval.

Short Answer

Expert verified

The required correct option is(e)

Step by step solution

01

Given information

Confidence interval =90卤30

Confidence level=90%

02

The objective is to find out the 95%confidence interval using the same data

The width of the confidence interval is known to be proportional to the sample size. As a result, the width of the interval would become wider for the sample data at 95%confidence level. The sample size must be known in order to compute the confidence interval.

Therefore, the correct option is(e)

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