Question

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 12 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			No mindfulness training
Subject ID #	# of binges		Subject ID #	# of binges
1	6		11	7
2	4		12	8
3	4		13	6
4	5		14	9
5	3		15	4
6	4		16	6
7	5		17	6
8	5		18	8
9	7		19	9
10	3		20	8
			21	7
			22	5

1. a) Calculate standard deviation of the comparison distribution

1. b) Calculate the t statistic

1. c) Considering the research question and the hypotheses, should the test be one-tailed or two-tailed? Why?

1. d) Determine the critical t value(s) for this hypothesis test based on the degree of freedom, from (d), and the preset alpha level.

1. e) Compare the calculated t statistic with the critical t value by stating which is more “extreme”, and then make a decision about the hypothesis test by stating clearly “reject” or “fail to reject” the null hypothesis.

f) Calculate the pooled standard deviation for the populations and then use it to calculate the standardized effect size of this test.

Answer 1

PL??