Source of variation

SS

df

MS

F

Scheffe

Grade

Freshman

1.52

1

1.52

6.08*

male > female

Sophomore

1.63

1

1.63

10.30**

male > female

Junior

1.03

1

1.03

3.35

Senior

0.86

1

0.86

3.76

Gender

Male

0.67

3

0.22

0.74

Female

2.58

3

0.86

5.07**

senior > freshman

senior > sophomore

senior > junior