Chapter 8.6, Problem 8.87ACI

Shopping vehicle and judgment. Refer to the Journal of Marketing Research (December 2011) study of shopping cart design, Exercise 2.85 (p. 88). Recall that design engineers want to know whether the mean choice of vice-over-virtue score is higher when a consumer’s arm is flexed (as when carrying a shopping basket) than when the consumer’s arm is extended (as when pushing a shopping cart). The average choice score for the n₁ = 11 consumers with a flexed arm was ${\bar{x}}_1=59,$ while the average for the n₂ = 11 consumers with an extended arm was ${\bar{x}}_2=43.$ In which scenario is the assumption required for a t-test to compare means more likely to be violated, s₁ = 4 and s₂ = 2, or, s₁ = 10 and s₂ = 15? Explain.