Practice Problem Answer: TWO-FACTOR ANOVA

A research study was conducted to examine the impact of eating a high protein breakfast on adolescents' performance during a physical education physical fitness test. Half of the subjects received a high protein breakfast and half were given a low protein breakfast. All of the adolescents, both male and female, were given a fitness test with high scores representing better performance. Test scores are recorded below.

1. Complete the following ANOVA table.

   
   

   Source	SS	df	MS	F
   Protein Level	20	1	20.00	8.89
   Gender	45	1	45.00	20.00
   Protein Level x Gender	5	1	5.00	2.22
   Within	36	16	2.25
   Total	106	19

   
   

2. Graph your data.

   

3. Are there any significant main effects or an interaction effect.

   There appears to be significant main effects for both protein level (F=8.89 (1,16), p<.01) and gender (F=20.00 (1,16), p<.01). There was not a significant interaction effect (F=2.22 (1,16), not significant).

4. Interpret your answer.

   Based on this data, it appears that a high protein diet results in a better fitness test score. Additionally, young men seem to have a significantly higher fitness test score than women.