Question

Answer the following questions based on the summary table below

Source	SS	df	MS	F
Subjects	850	13
Time	204	2	102	3.4
Error	780	26	30

1. How many people were in the study?

2. How many times was the dependent variable measured in each person?

3. What should be concluded about the effect of time on the dependent variable? Justify your answer by providing the appropriate critical value, assuming alpha = 0.05.

Answer 1

1. The total degree of freedom (df) is 13 +2 +26 = 41

Then total number of observations are 41+1 = 42.

2. There are 3 times were measured in each person. Because the df of the factor time is 2.

3. If observed F = 3.4 > F_{0.05; 2,26} we conclude that there is a significant difference among the times. Otherwise we say time doesn't differ significantly.

Now F_0.05;2,26 = 3.37 so ,

Observed F > tabulated F

So, we can conclude that there is a significant difference among times.