Please explain how to solve the second part. Thank you in advance.

X 7.1.33-T Question Help 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 99%. Complete parts (a) through (c) below. a. Assume that nothing is known about the percentage to be estimated. n = 664 (Round up to the nearest integer.) b. Assume prior studies have shown that about 60% of full-time students earn bachelor's degrees in four years or less. n =] (Round up to the nearest integer.)