An epidemiologist plans to conduct a survey to estimate the percentage of women who give birth. How many women must be surveyed in order to be 95% confident that the estimated percentage is in error by no more than two percentage points? Complete parts (a) through (c) below.

a. Assume that nothing is known about the percentage to be estimated.

n = 

(Round up to the nearest integer.)

b. Assume that a prior study conducted by an organization showed that 81% of women give birth.

n=