We would like to estimate the average age of the students in

We would like to estimate the average age of the students in the BSN program. We want to be 99% confident that the estimate should be accurate within 1 year. From previous surveys, we know the standard deviation of the ages is known to be 3 years. How large a sample is necessary? Please show your work whether you use the formula or EpiCalc.

Solution

Compute Sample Size
n = (Z a/2 * S.D / ME ) ^2
Z/2 at 0.01% LOS is = 2.58 ( From Standard Normal Table )
Standard Deviation ( S.D) = 3
ME =1
n = ( 2.58*3/1) ^2
= (7.74/1 ) ^2
= 59.91 ~ 60