Question

13a. Jessica thinks that college major and year of study affect performance on a standardized math test. To determine if she is right, Jessica recruits a sample of 80 students for her experiment. Of her 80 students, Jessica recruits 20 students who are freshmen, 20 who are sophomores, 20 who are juniors and 20 who are seniors. Ten students from each year of study are Psychology majors and the other 10 students from each year of study are Math majors. Fill in the table below.

	SS	Df	MS	F
Between
College Major
Year of Study			20
CollMaj x YrStudy				5
Within	144
Total	234

13b. Is there a significant main effect of college major?

13c. Is there a significant main effect of year of study?

13d. Is there a significant interaction between college major and year of study?

Answer 1

for above table:

Source	SS	df	MS	F
between	90	7
major	0	1	0.00	0.00
year	60	3	20.00	10.00
interaction	30	3	10.00	5.00
within	144	72	2.00
total	829	79

13b)  Is there a significant main effect of college major : No (since the F statstic is not significant)

13c) Yes since F =10 is higher than critical value 2.73 at 0.05 level

13d) Yes since F =5 is higher than critical value 2.73 at 0.05 level

1