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In each of the following situations, discuss whether it would be appropriate to construct a one-sample tinterval to estimate the population mean.

(a) We want to estimate the average age at which U.S. presidents have died. So we obtain a list of all U.S. presidents who have died and their ages at death.

(b) How much time do students spend on the Internet? We collect data from the 32members of our AP Statistics class and calculate the mean amount of time that each student spent on the Internet yesterday.

(c) Judy is interested in the reading level of a medical journal. She records the length of a random sample of 100words from a multipage article. The Minitab histogram below displays the data.

Short Answer

Expert verified

(a) We do not use t-procedure.

(b) We do not use t-procedure.

(c) We can uset-procedure.

Step by step solution

01

Part(a) Step 1: Given Information

02

Part(a) Step 2: Explanation

The sample contains the entire population, thus we can calculate the population mean directly and this means that it is not necessary to use the t-procedure.

03

Part(b) Step 1: Given Information

04

Part (b) Step 2: Explanation

The sample is a convenience sample because the individuals were conveniently selected as the members of the class.

A convenience sample is NOT a random sample and thus the RANDOM requirement for the t-procedure is not satisfied.

05

Part(c) Step 1: Given Information

06

Part(c) Step 2: Explanation

There are 3requirements to use the t-procedure: Random, Independent, Normal

Random: The sample is given to be a random sample

Independent: Can be assumed, because the sample size of 100is less than 10%of the population size.

Normal: Can be assumed, because the sample size of 100is larger than 30.

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