Well that was fun, but you have been pulled back to the campaign fundraiser, because a donor is concerned about the chances your candidate is concerned, Geoff Picton, can win the primary since they believe too many primary voters have already made their final decision.

So, you want to estimate the proportion of registered Democrats in Jefferson state who "are sure which candidate they will vote for in the primary."

A.What sample size should be obtained if you want to be within 4 percentage points with 94% confidence if you use an estimate of 48% obtained from a poll?

B.What sample size should be obtained if you want to be within 4 percentage points with 94% confidence if you do not use any prior estimates?

C.Why are the results from parts (a) and (b) so close?