Question

Suppose the incubation period for certain types of cold viruses are normally distributed with a population standard deviation of 8 hours. Use Excel to calculate the minimum sample size needed to be 99% confident that the sample mean is within 4 hours of the true population mean.

Be sure to round up to the nearest integer.

Answer 1

We have given here,                  
                  
Population standard deviation =   8  
Margin of error =E=4  
Level of significance =1-0.99=0.01  
Z critical value is (by using Z table)=2.576  
Sample size formula is                   


=26.54