Bachelor’s Degree in Four Years In a study of government financial aid for college students, it becomes necessary to estimate the percentage of full-time college students who earn a bachelor’s degree in four years or less. Find the sample size needed to estimate that percentage.

Use a 0.05 margin of error, and use a confidence level of 95%.

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

b. Assume that prior studies have shown that about 40% of full-time students earn bachelor’s degrees in four years or less.

c. Does the added knowledge in part

(b) have much of an effect on the sample size?