A researcher performs a 3x5 ANOVA examining how preferences

A researcher performs a 3x5 ANOVA examining how preferences for engagement with friends varied as a function of age (20, 30, 40 year olds) and social media tools facebook, twitter, linkedin, goggle+,instragram with 26 participants in each cell of the study design. What is the degrees of freedom for the variable age?

Solution

Degrees of freedom between = k - 1 = 3 - 1 = 2                              
Degrees of freedom Within = n - k = 15 - 3 = 12                              
                              
Degrees of freedom Total F( k-1,n - k,) at 0.05 is = F Crit = 3.885