Question

Use the margin of error of 4, confidence interval of 90% and ?=28 to find the minimum sample size required to estimate an unknown population mean ?. (If using TI-84 plus, show steps)

Answer 1

We have given here,                  
                  
Population standard deviation =   28  
Margin of error =E=4  
Level of significance =   1-0.90=0.1  
Z critical value is (by using Z table)=1.645  
Sample size formula is                   


=132.6

Sample size