Political polls typically sample randomly from the US popula

Political polls typically sample randomly from the U.S population to investigate the percentage of voters who favor some candidate or issue. Suppose that one such poll asks voters how they feel about the President

Solution

We use p=0.5 as estimated.

Given a=0.05, Z(0.025) = 1.96 (from standard normal table)

So the sample size is

n=(Z/E)^2*p*(1-p)

=(1.96/0.02)^2*0.5*0.5

=2401