Question

Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be $90 \%$ confident that the population mean is within 10 minutes of the sample mean? Assume the population standard deviation is 42 minutes.

          Internet Viewing A researcher wishes to estimate
the average number of minutes per day a person
spends on the Internet. How large a sample must
she select if she wishes to be $90 \%$ confident that the
population mean is within 10 minutes of the sample
mean? Assume the population standard deviation is
42 minutes.

Added by Blanca S.

Instant Answer

Solved by Expert Ajiboye Tunde

11/09/2021

Step 1

645 (you can find this value in a standard Z-score table). The standard deviation σ is given as 42 minutes, and the desired margin of error E is 10 minutes. Substituting these values into the formula, we get: n = (1.645*42/10)^2 n = 47.07 Since we can't have a Show more…

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Internet Viewing A researcher wishes to estimate the average number of minutes per day a person spends on the Internet. How large a sample must she select if she wishes to be $90 \%$ confident that the population mean is within 10 minutes of the sample mean? Assume the population standard deviation is 42 minutes.