Question

A television sports commentator wants to estimate the proportion of Americans who follow professional football. What sample size should be obtained if he wants to be within 3 percentage points with 95% confidence if

(a) he uses a 2010 estimate of 53% obtained from a Harris poll?
(b) he does not use any prior estimates?
(c) Why are the results from parts (a) and (b) so close?

Answer 1

A.1,063

B.1.067

C.Since 0.2491 is close 0.25 this means that the results from parts (a) and (b) are close.

Explanation:

A. If he uses a 2010 estimate of 53% obtained from a Harris poll

Since E is 0.03

The next stel is to find Z using this formula