Practice Problem Answer: TWO-FACTOR ANOVA




A study examining differences in life satisfaction between young adult, middle adult, and older adult men and women was conducted. Each individual who participated in the study completed a life satisfaction questionnaire. A high score on the test indicates a higher level of life satisfaction. Test scores are recorded below.

Group Young Adult Middle AdultOlder Adult
Male4
2
3
4
2

Mean=3.0

7
5
7
5
6

Mean=6.0

10
7
9
8
11

Mean=9.0

Female7
4
3
6
5

Mean=5.0

8
10
7
7
8

Mean=8.0

10
9
12
11
13

Mean=11.0


  1. Complete the following ANOVA table.


    SourceSSdfMSF
    Age180290.0049.09
    Gender30130.0016.36
    Age x Gender020.000.00
    Within 44 24 1.83
    Total25429


  2. Graph your data.

  3. Are there any significant main effects or an interaction effect.

    Without post hoc tests it is difficult to know where differences lie specifically. There are significant main effects for age (F=49.09 (2,24), p<.01) and gender (F=16.36 (1, 24), p<.01). There is no interaction effect (F=0.00 (2,24), not significant).

  4. Interpret your answer.

    I appears from the data that older adults have the highest life satisfaction and younger adults have the lowest life satisfaction. Women also have significantly higher life satisfaction than men.




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