A doctor at a local hospital is interested in estimating the birth weight of infants. How large a sample must sheselect if she desires to be 90% confident that her estimate is within 2 ounces of the true mean? Assume that s =5 ounces based on earlier studies.
A) 17
B) 16
C) 5
D) 4

Question

Quizplus · Accepted Answer

To determine the sample size, use the formula for the sample size of a mean: n = (Z*s/E)^2. For 90% confidence, Z is approximately 1.645. Plugging in the values: n = (1.645*5/2)^2 = 16.96, which rounds up to 17.

A Doctor at a Local Hospital Is Interested in Estimating