Question

A simple random sample of 85 is drawn from a normally distributed population, and the mean is found to be 146, with a standard deviation of 34. Which of the following values is outside the 99% confidence interval for the population mean?

Answer 1

anything below 136.5 or above 155.5

Explanation:

the critical value from a Z distribution for the 99% confidence level is 2.576

so we just need to compute

146 + 2.576(34/sqrt(85))

and

146 + 2.576(34/sqrt(85))

Answer 2

A. the value of 135 because it is not greater than 136.5