Question: Conspicuous consumption and men's testosterone levels. It is argued that conspicuous consumption is a means by which men communicate their social status to prospective mates. One study looked at changes in a male's testosterone level in response to fluctuations in his status created by the consumption of a product. The products considered were a new and luxurious sports car and an old family sedan. Participants were asked to drive either on an isolated highway or a busy urban street. A table of cell means and standard deviations for the change (posttreatment level minus pretreatment level) in testosterone follows:

(a) Make a plot of the means and describe the patterns that you see. Does the plot suggest an interaction between location and type of car?

(b) Compute the pooled standard error sp, assuming equal sample sizes

(c) The researchers wanted to test the following hypotheses:

1. Testosterone levels will increase more in men who drive the new car.

2. For men driving the new car, testosterone levels will increase more in men who drive in the city.

3. For men driving the old car, testosterone levels will decrease less in men who drive the old car on the highway. Write out the contrasts for each of these hypotheses.

(d) This study actually involved each male participating in all four combinations. Half of them drove the sedan first and the other half drove the sports car first. Explain why a "repeated-measures'' design like this may be beneficial.