How large a sample should be selected to provide a 95 confid

How large a sample should be selected to provide a 95% confidence interval with a margin of error of 10 (to the nearest whole number)? Assume that the population standard deviation is 40.

Compute Sample Size
n = (Z a/2 * S.D / ME ) ^2
Z/2 at 0.05% LOS is = 1.96 ( From Standard Normal Table )
Standard Deviation ( S.D) = 40
ME =10
n = ( 1.96*40/10) ^2
= (78.4/10 ) ^2
= 61.466 ~ 62