A political polling firm is conducting a poll in order to determine which candidate is likely to win an upcoming election. The polling firm interviews likely voters and asks each whether or not they will vote for the republican (R) or the democrat (D) candidate. They then tabulate the percentage that respond R and D
(a) How many voters should the firm poll in order to correctly estimate the correct proportion of R and D respondents in the general population to within
percentage points with 90% probability?
(b) Repeat part (a) if we want 95% confidence in our polling data.