1.A doctor wants to estimate the HDL cholesterol of all20- to29-year-old females. How many subjects are needed to estimate the HDL cholesterol within 3

3 points with 99 %

99% confidence assuming sigma equals 11.5 question mark

=11.5? Suppose the doctor would be content with 90 %

90% confidence. How does the decrease in confidence affect the sample sizerequired?

A99% confidence level requires -----

subjects.

2.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

95% confidence? Initial survey results indicate that sigma

equals=17.5

17.5 books.

A 95 % confidence level requires subjects.