13.8 Determining the critical value of F. For each of the following situations, state how large the F statistic needs to be for rejection of the null hypothesis at the 5% level. Sketch each distribution and indicate the region where you would reject.

  1. (a) The main effect for the first factor in a 2 × 5 ANOVA with three observations per cell.

  2. (b) The interaction in a 3 × 2 ANOVA with six observations per cell.

  3. (c) The interaction in a 2 × 3 ANOVA with six observations per cell.