Determine the sample size necessary to estimate p for the following information.
a. E = .02, p is approximately .40, and confidence level is 96%
b. E is to be within .04, p is unknown, and confidence level is 95%
c. E is to be within 5%, p is approximately 55%, and confidence level is 90%
d. E is to be no more than .01, p is unknown, and confidence level is 99%