Q. 44 Mary was interested in comparing... [FREE SOLUTION]

91影视

The Practice of Statistics for AP Examination

Daren Starnes, Josh Tabor

$Math Studyset 91影视 Explanations$ Math

6th Edition 路 837 pages

ISBN: 9781319113339

Chapter 10: Q. 44 (page 666)

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 $400$ words of an article in the medical journal and in the first $100$ words of an article in the airline magazine. Mary then used statistical software to produce the histograms shown.
Let $渭_{M J} =$ the true mean length of all words in the medical journal and $渭_{A M} =$ the true mean length of all words in the airline magazine. Check if the conditions for calculating a confidence interval for $渭_{M J} - 渭_{A M}$ are met.

Short Answer

Expert verified

Random condition is not satisfied.

Step by step solution

Step 1. Given information

Given:

Step 2. Explanation

We have to check if the conditions are met or not. Therefore,

There are three conditions to be satisfied:

Random: It is not satisfied because the samples are not independent random samples as we conveniently select the first $400$ words and the first $100$ words of the two article.

Independent: It is satisfied because the $400$ words is less than $10 %$ of the population of all words in the medical journal and the sample of $100$ words is less than $10 %$ of the population of all words in the airline magazine.

Normal: It is satisfied because the two samples are large and since $100 i s a t l e a s t 30$ and role="math" localid="1664190569522" $400 i s a t l e a s t 30$ .

Thus, all the conditions are not satisfied since random condition is not satisfied and it is not appropriate to determine a confidence interval for the mean difference.