Question

Ted Works in the digital Acquisitions Department of the Vindale Public Library. The library is looking into switching some of its Holdings to a digital format. As part of a preliminary study, Ted randomly choose 150 books from the library's collection and found and 73 of them are available is e-books. Estimate the proportion of the library's collection that are available as e-books. including a margin of error.

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Answer 1

c. 48.67% ± 8.16%

Explanation:

The proportion is:

p = 73 / 150 = 0.4867

The margin of error is:

ME = z √(p (1 − p) / n)

where z is the critical value, p is the proportion, and n is the sample size.

For a 95% confidence interval, z ≈ 2.

ME = 2 √(0.4867 (1 − 0.4867) / 150)

ME = 0.0816

So the proportion is 48.67% ± 8.16%.

Answer 2

c. 48.67% ± 8.16%

Explanation:

Ted Works in the digital Acquisitions Department of the Vindale Public Library. The library is looking into switching some of its Holdings to a digital format. As part of a preliminary study, Ted randomly choose 150 books from the library's collection and found and 73 of them are available is e-books. Therefore, estimating the proportion of the library's collection that are available as e-books. including a margin of error is 48.67% ± 8.16%.