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The university is interested in investigating whether the mean GPA of all colleg

ID: 2908905 • Letter: T

Question

The university is interested in investigating whether the mean GPA of all college students differs for various years in college. Samples were selected and the data was analyzed in Statistix to determine if the average GPA of sophomores, juniors, and seniors differed. The analysis is shown below:

One-Way AOV for GPA by Year

Source DF SS MS F P
Year 2 2.7978 1.39889 9.81 0.0001
Error 85 12.1163 0.14255
Total 87 14.9141

Grand Mean 3.2259 CV 11.70

Bonferroni All-Pairwise Comparisons Test of GPA by Year

Year Mean Homogeneous Groups
Sophomore 3.7500 A
Junior 3.1847 B
Senior 3.1360 B

Alpha 0.05

Which of the following assumptions are necessary for this analysis to be valid?

The samples were independently selected from the other samples

Explanation / Answer

The assumptions required for ANOVA test are

1) The samples are random and independent.

2) The samples are drawn from normal populations.

3) The samples are drawn from populations of homogenous variances.

So the correct option is

All of the above are necessary