Question

Suppose that the pages per book in a library are normally distributed with an unknown mean and standard deviation. The book lengths of 39 randomly sampled books are used to estimate the mean of the population. What t-score should be used to find the 99% confidence interval for the population mean?

Answer 1

A t-score of 2.0244 should be used to find the 99% confidence interval for the population mean

Explanation:

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 39 - 1 = 38

Now, we have to find a value of T, which is found looking at the t table, with 38 degrees of freedom(y-axis) and a confidence level of 0.99(
`t_(99)`). So we have T = 2.0244.

A t-score of 2.0244 should be used to find the 99% confidence interval for the population mean