Question

If you want to be 99% confident of estimating the population mean to within a sampling error of 16 and the standard deviation is assumed to be 17. what sample size is required? The sample size required is - (Round up to the nearest integer.)

Answer 1

We have given here,                  
                  
Population standard deviation =17  
Margin of error =E=6  
Level of significance =   0.01  
Z critical value is (by using Z table)=   2.576  
Sample size formula is                   
$n=\left [ \frac{Z*\sigma}{E} \right ]^{2}$

=53.27  

「2.576 + 17]

$\approx 54$