Question

You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 99% confident that you estimate is within 3% of the true population proportion. How large of a sample size is required?

n =

Answer 1

We have given,
Preliminary estimate for proportion not known=   0.5
Margin of error =E=0.03
Level of significance =1-0.99=0.01
Z critical value is (by using Z table) =2.576
Sample size formula is                   

n = [p(1 – P)]


= [0.5 *(1-0.5] | ||

=1843.27      

n 1844