Need help with some questions.

1)People were polled on how many books they read the previous year. How many subjects are needed to estimate the number of books read the previous year within one book with 95% confidence? Initial survey results indicate that =10.2 books.

A 95% confidence level requires______? subjects.

(Round up to the nearest whole number as needed.)

2) Find the minimum sample size n needed to estimate for the given values of c, , and E.

c=0.98, =9.9, and E=2

Assume that a preliminary sample has at least 30 members.

n=_____?

(Round up to the nearest whole number.)

3) A doctor wants to estimate the HDL cholesterol of all 20- to 29-year-old females. How many subjects are needed to estimate the HDL cholesterol within 44 points with 99% confidence assuming =19.5? Suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required?

A 99% confidence level requires_____? subjects.

(Round up to the nearest whole number as needed.)