Table 10.17 shows subjects€™ purchase choice of instant decaffeinated coffee at two times.

a. Fit the symmetry model and use residuals to analyze changes.

b. Test marginal homogeneity. Show that the small P-value reflects a decrease in the proportion choosing High Point and an increase in the proportion choosing Sanka, with no evidence of change for the other coffees.

c. Show that quasi-independence has G² = 13.8 (df = 11). Interpret, and suggest other analyses that might be useful.

Table 10.17:

Transcribed Image Text:

Second Purchase First Purchase Taster's Choice High Point Sanka Nescafe Brim High Point 93 17 46 11 4 4 44 11 155 10 Taster's Choice 12 2 27 Sanka 17 Nescafe 15 2 Brim 12 10