An experiment is conducted to study the effects of two sales approaches€”high-pressure (H) and low- pressure (L)€”and to study the effects of two sales pitches (1 and 2) on the weekly sales of a product. The data in Table 11.13 on the next page are obtained by using a completely randomized design, and Figure 11.14 gives the Excel output of a two- way ANOVA of the sales experiment data. Using Table 11.13 and the computer output of Figure 11.14:

a. Perform graphical analysis to check for interaction between sales pressure and sales pitch.
b. Test for interaction by setting α = .05.
c. Test for differences in the effects of the levels of sales pressure by setting α = .05.
d. Test for differences in the effects of the levels of sales pitch by setting α = .05.

ANOVA: Two-Factor With Replication SUMMARY Pitch 1 Pitch 2 Tot High Pressure Count Sum Average Variance 91 30.3333 2.3333 181 30 30.1667 4 25667 90 Low Pressure Count Sum Average Variance 76 25.3333 6.3333 148 24 24.6667 1 34667 72 Total Count Sum Average Variance 167 16:2 27 27.8333 10.9667 12.8 ANOVA Source of Variation SS df Pressure Pitch Interaction Within Total F P-value F crit 90.75 90.75 26.5610 0.0009 5.3177 2.0833 2.0833 0.6098 04574 5.3177 0.75 0.75 0.2195 0.6519 5.3177 MS 27.3333 120.917 8 11 3.4167