A two-factor analysis of variance is used to evaluate the significance of the mean differences for the two-factor research study shown in the following table. The study is evaluating the effects of sugary versus non-sugary snacks on the activity level of preschool children. Identify the three F-ratios and, using the following data from a 2 × 2 design, identify the means (or mean differences) that are compared by each F-ratio.

Before Snack After Snack M = 22 M = 24 Sugary snack Nonsugary Snack M = 20 M = 24 M = 26 M = 25 M = 22 Overall M = 21