Chapter 12: 9,10 and the following:
An experiment was done to see if cash offers for used cars varied
according to the age of the owner. Twelve actors in each of three
categories: Young, Middle, and Elderly (36 in all) used the same
car to solicit cash offers from 36 randomly selected car dealers.
Half of the actors in each group were male, half female. The data
are shown below, but can be summarized as follows:
SSA = 316.722, SSB = 5.444, SSAB = 5.056, SSE = 71.667.
- 1) Obtain the estimated means for each cell and make a cell plot graph.
- 2) Obtain the estimated values for the parameters of the two-way model.
- 3) Is there an interaction effect?
- 4) Is there a gender effect?
- 5) Is there an age effect?
- 6) Calculate the residuals and plot versus treatment group. What
departures from the ANOVA model can be studied from such plots? Do
you see any evidence of such departures here?