Question

The librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant took a sample and found the mean to be 880 books. She provides the librarian with an interval estimate of between 790 and 970 books checked out per day. An efficient, unbiased point estimate of the number of books checked out each day at the Library of Congress is

Answer 1

a. 880

Explanation:

Options are "a. 880 b. 90 c. 790 d. None of these choices"

Interval estimate of between 790 and 970 books checked out per day.

Lower limit is 790, Upper limit is 970

Point estimate of μ(x) = [Upper limit + Lower limit} / 2

Point estimate of μ(x) = [970 + 790] / 2

Point estimate of μ(x) = 1760/2

Point estimate of μ(x) = 880

So, the efficient, unbiased point estimate of the number of books checked out each day at the New York City Public Library is 880.