simple pre-test/post-test study, a dependent samples t test, statistics homework help

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simple pre-test/post-test study, a dependent samples t test, statistics homework help

20) Sally conducts a simple pre-test/post-test study to determine how much food waste is accumulated in Commons before and after the college decides to remove all trays (upon which to carry plates, glasses, etc.) from the dining hall. She runs a dependent samples t-test and finds that t is a negative value. Because t is negative, she’s worried she’s done something wrong. Has she? Why or why not (explain why it is or is not possible to get a negative t-value in this case). (2 points)

21) Researchers conduct a between-subjects factorial ANOVA (also known as a two-way ANOVA) which looks at the effects of sex and age group (not raw age) on self-esteem scores (which can range from 10 to 40). 

a) List the independent variables and their levels in this example. (2 pts)

b) What are the 3 specific null hypotheses that can be tested in this example? (3 pts)

c) The results of the ANOVA are pasted on the next page. Which of the three null hypotheses should we reject? Why? (2 pts)