Question

A researcher wanted to conduct a study to assess the influence of social exclusion on stress eating among African American women. In this study, participants played a computer-based simulated game of catch with 3 other participants in which the participants were either included or excluded and saw either African American or Caucasian faces. Specifically, the 20 participants were randomly assigned into 1 of the following 4 groups: Group 1 in which participants saw African American faces and were included, Group 2 in which participants saw Caucasian faces and were included, Group 3 in which participants saw African American faces and were excluded, and Group 4 in which participants saw Caucasian faces and were excluded. After playing the game for 5 minutes, participants were provided 130 grams of snack foods and were left alone for an additional 5 minutes. The data in the table below show the amount(s) of food (in grams) participants ate:

	Group 1	Group 2	Group 3	Group 4
	75	90	115	130
	55	80	110	125
	69	60	100	120
	73	75	113	128
	50	85	105	117
Total(s)	322	390	543	620

According to this data, is there a difference in the mean number of grams of food participants ate at a 5% level of significance?

1. Set up hypotheses and indicate level of significance.

H0:

H1:

α =

2. Indicate the appropriate test statistic.

3. Set up decision rule.

df1 = k – 1 = ________________________________________________________

df2 =N – k = ________________________________________________________

Reject H0 if F > _____________________________________________________

4. Compute the test statistic.  

            

Group 1	Group 2	Group 3	Group 4
n1 =	n2 =	n3 =	n4 =
1=	2=	3=	4=

Compute the overall mean: =

Answer 1