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a stats professor is trying to choose between 3 textbooks. To him decide, he ran

ID: 3159785 • Letter: A

Question

a stats professor is trying to choose between 3 textbooks. To him decide, he randomly assigns a group of 18 students to go through the books and rate how much they like them. Six students rate the first book six students rate the second book, and six students rate the third book. Each students gives the book they read a rating from 1 to 10. Their ratings are listed below.

Book 1      Book2      Book 3

8                4              5

7                 6              9  

10              3             8

6                4                10

5                8                8

10               3            8

is there a significant difference among the books? be sure to include a discussion of the critical value in your answer.

Explanation / Answer

The data is imported to R statistical software and then a chi-square test is performed on it.

> books <- read.csv("clipboard",sep=" ")
> books
B1 B2 B3
1 8 4 5
2 7 6 9
3 10 3 8
4 6 4 10
5 5 8 8
6 10 3 6

> chisq.test(books)

        Pearson's Chi-squared test

data: books
X-squared = 8.316, df = 10, p-value = 0.598

Warning message:
In chisq.test(books) : Chi-squared approximation may be incorrect

Since the p-value is large, there is no significant difference among the books.