Q3) More Practice with Standard Error in the Independent Samples t-Test (15 points total)

We'll calculate the actual t-statistic next week.

An eating disorders clinic would like to evaluate the effectiveness of a mindfulness training program on binge eating disorder (BED). A psychologist was therefore hired to conduct a small study to examine the potential effect of mindfulness training on number of binges per month. The psychologist recruited 10 patients in the clinic to participate in a mindfulness training program and 10 patients in the clinic with similar demographics who do not participate in the mindfulness program. Afterward, all participants reported the number of binges from the previous month. The data are listed in the table below. The psychologist is not predicting a particular direction of the potential differences between the two groups and she sets the alpha level at .05 for the hypothesis test.

Mindfulness Training

Subject ID# # of binges

1 6

2 4

3 4

4 4

5 3

6 4

7 4

8 5

9 7

10 3

No Mindfulness Training

Subject ID # # of binges

11 7

12 8

13 5

14 9

15 4

16 6

17 6

18 8

19 9

20 8

a)What is the dependent (outcome) variable? What is the independent (grouping) variable? (1 points total: .5 per variable)

b)Create the null and alternative hypotheses for this study, using either words or symbol notation (2 points total: 1 point per hypothesis)

c)Calculate M₁ and M₂ (2 points total: 1 point per sample mean- .5 for work, .5 for answer)

d)Calculate df₁ , df₂, and df_total(2 points total: 1 for df1 and df2, 1 for total df, including work)

e)Calculate the sum of squares (Sum of squared deviations) for both samples (4 points total: 2 points for each sum of squares. 1 for work and 1 for result)

f)Calculate the pooled variance for the two populations (2 points total: 1 point for work, 1 point for result)

g)Use the pooled variance to calculate the standard error of the mean differences (2 points total: 1 for work and 1 for result)