Consider the 3 4 ANOVA with 36 observations in Example 9.5. Keeping the experiment-wise error rate at 10%, calculate the MSD required to declare two cell means significantly different in each of the...

Consider the 3

4 ANOVA with 36 observations in Example 9.5. Keeping the experiment-wise error rate at 10%, calculate the MSD required to declare two cell means significantly different in each of the following situations.

(a) We want to find the best combination(s) of N and P, out of the 12 choices.

(b) The only comparisons of interest are for each of the four possible values of P, find the best choice of N.

(c) The only comparisons of interest are for each of the three possible values of N, find the best choice of P.

(d) We will freely explore all pairwise comparisons and any other contrast that occurs to us after examining the profile plot.

Example 9.5

This experiment concerns the search for some optimum levels of two fertilizer ingredients, nitrogen (N) and phosphorus (P). We know that there is likely to be an interaction between these two factors. The data are shown in Table 9.12. Notice that the levels of N and P are actually quantities of fertilizer per unit of area. That is, N and P are quantitative factors.