Question

If there are 5 levels of Factor A and 7 levels of Factor B for an ANOVA with interaction, what are the interaction degrees of freedom?

a. 24.

b. 12.

c. 10.

d. 35.

Answer 1

C. 10

Explanation:

let n1 be the degree of freedom of factor A

Let n2 be the degree of freedom of factor B

If there are 5 levels of factor A, then n1 = 5

If there are 7 levels of Factor B then n2 = 7

The interaction between the degrees of freedom is expressed using the formula;

df = (n1 - 1)+(n2 - 1)

df = n1 -1 + n2- 1

df = n1+n2 -2

Substitute n1 and n2 and get df

df = 5+7-2

df = 12-2

df = 10

Hence the interaction degree of freedom is 10