Please help me understand factorial ANOVA

These are my lecture slides, at the end you will see that the table with the answers is filled out. I do not understand how my prof got to these answers!

Please help me!

I added the formulas below:

Factorial ANOVA 24 students, 6 in each cell. Two factors (independent variables) with 2 levels each ( 22 factorial analysis): Columns (C1 and C2): Course Difficulty: relatively easy or difficult. Rows (R1 and R2): Peer tutors: either provided or not. Dependent variable: performance in course The Source Table Each main effect (IV) and each interaction has its own F to be evaluated, using its own dfbetween and dferror Calculations: SS SStotal=(xxg)2SSIV1=nkIV2(xiIV1xg)2SSIV2=nkIV1(xiIV2xg)2 SScells=n(xxg)2 Sum of squared deviations between each score and the grand mean Sum of squared deviations between each mean on this IV (collapsed over other IV) \& the grand mean, multiplied by number of people per group and number of levels of other IV Sum of squared deviations between each group mean (not collapsed over IVs) \& the grand mean, multiplied by number of people per group. Dummy term to simplify other calculations. 22 Calculations: SS (con't) SSinteraction=SScellsSSIV1SSIV2SSerror=SStotalSScells Calculations: df dfIV1=kIV11dfIV2=kIV21dfinteraction=dfIV1dfIV2=(kIV11)(kIV21)dferror=dftotaldfIV1dfIV2dfinteraction=kIV1kIV2(n1)dftotal=N1 - MS: Divide SS by df for each source - F: Divide each MS by MS What does this tell us? Fcrit(1,20)=4.35 Row effect (main effect) Column effect (main effect) The interaction