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Chapter 10: Q. 42 (page 653)

42. Long words Mary was interested in comparing the mean word length in articles from a medical journal and an airline鈥檚 in-flight magazine. She counted the number of letters in the first 200 words of an article in
the medical journal and in the first 100 words of an article in the airline magazine. Mary then used Minitab statistical software to produce the histograms shown.

Short Answer

Expert verified

The random requirement was not met.

Step by step solution

01

Given information

Mary counted the number of letters in the first 200 words of an article in
the medical journal and in the first 100 words of an article in the airline magazine.

02

Explanation

Determine the Random, Normal, and Independent are the requirements from the given histogram:

Random, Normal, and Independent are the requirements for two-samplet methods.
The samples of words were conveniently chosen as the first 200words, which are not representative of all words, hence the Random requirement was not met.

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Most popular questions from this chapter

Researchers are interested in evaluating the effect of a natural product on reducing blood pressure. This will be done by comparing the mean reduction in blood pressure of a treatment (natural product) group and a placebo group using a two-sample t-test. The researchers would like to be able to detect whether the natural product reduces blood pressure by at least 7points more, on average than the placebo. If groups of size 50are used in the experiment, a two-sample t-test using role="math" localid="1650436089340" 伪=0.01will have a power of 80%to detect a 7-point difference in mean blood pressure reduction. If the researchers want to be able to detect a 5-point difference instead, then the power of test

(a) would be less than 80%.

(b) would be greater than 80%.

(c) would still be 80%.

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(d) should not be used because the Random condition is violated

(e) should not be used because the Normal condition is violated.
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