Question

Assume that you want to construct a​ 95% confidence interval estimate of a population mean. Find an estimate of the sample size needed to obtain the specified margin of error for the​ 95% confidence interval. The sample standard deviation is given below.

Margin of errors=​$6​,

standard deviation=​$22

The required sample size is __

Answer 1

We have given here,              
              
Standard deviation =$22
Margin of error =E=$6
Level of significance =   1-0.95=0.05
Z critical value is (by using Z table)=1.96
Sample size formula is               


=51.65