Confidence interval

Hope someone can help....

1. You are to conduct a sample survey to determine the mean income of professionals working in a small urban city. How many professionals should be sampled? In a pilot sample of 85 professionals, the standard deviation of the sample was $800. The sponsor of the survey wants you to use the 95% confidence level. The estimate is to be within $500. How many professionals should be interviewed?

2. An urban economist wished to estimate the proportion of Canadians who own their home. What size of sample should be obtained if he wishes the estimate to be within
0.03 with a 99% confidence if he uses an estimate of 0.652 obtained from a housing
publication?

Thanks in advance.