Find the Necessary Sample Size

Multiple Choice

Find the necessary sample size.
-The weekly earnings of students in one age group are normally distributed with a standard deviation of 10 dollars. A researcher wishes to estimate the mean weekly earnings of students in
This age group. Find the sample size needed to assure with 95 percent confidence that the sample
Mean will not differ from the population mean by more than 2 dollars.

A) 10
B) 7
C) 20
D) 97