# ANOVA, F Scores and Hypothesis Testing

14. Foofy obtained a significant Fobt from an experiment with five levels. She therefore concludes that changing each condition of the independent variable. (a) Is she Correct? Why or why not? (b) What must she do now?

16. A report says that the between-subjects factor of participants' salary produced significant differences in self-esteem. (a) What does this tell you about the design? (b) What does it tell you about the results?

18. A researcher investigated the number of viral infections people contract as a function of the amount of stress they experienced during a 6-month period. She obtained the following data:

Amount of Stress

Negligible Stress Minimal Stress Moderate Stress Severe Stress

2 4 6 5

1 3 5 7

4 2 7 8

1 3 5 4

(a) What are H0 and Ha? (b) Compute Fobt and complete the ANOVA summary table. (c) With α = .05, what is Fcrit? (d) Report your statistical results. € Perform the appropriate post hoc comparisons. (f) What do you conclude about the study? (g) Describe the effect size and interpret it. (h) Estimate the value of µ that is likely to be found in the severe stress condition.

20. In a study in which k = 3, n = 21, (bar)X1 =45.3, (bar)X2 = 16.9, and (bar)X3 = 8.2, you compute the following sums of squares:

Source Sum of Squares df Mean Square F

Between 147.32 _______ _______ _____

Within 862.99 ______ _______

Total 1010.31 ______

(a) Complete the ANOVA summary table. (b) With α = .05 what do you conclude about Fobt? (c) Report your results in the correct format. (d) Perform the appropriate post hoc comparisons. What you do you conclude about this relationship? € What is the effect size in this study, and what does this tell you about the influence of the independent variable?

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14. Foofy obtained a significant Fobt from an experiment with five levels. She therefore concludes that changing each condition of the independent variable. (a) Is she Correct? Why or why not? (b) What must she do now?

She is not correct since a significant F indicates at least one of the independent variable could results in significant changes in the dependent variable. Therefore, in this case, she needs to perform posthoc test to figure out which independent variables could contribute significant changes in the dependent variable.

16. A report says that the between-subjects factor of participants' salary produced significant differences in self-esteem. (a) What does this tell you about the design? (b) What does it tell you about the results?

This tells us that the design could produce significant differences in self-esteem. It tells us that the results are significant between different groups of participants' salary.

18. A researcher investigated the number of viral infections people contract as a function of the amount of stress they experienced during a 6-month period. She obtained the following ...

#### Solution Summary

The f scores and hypothesis testing for ANOVA are examined. Post HOC comparisons are performed.