Payne (2001) gave participants a computerized task in which they first see a face and then a picture of either a gun or a tool. The task was to press one button if it was a tool and a different one if it was a gun. Unknown to the participants while they were doing the study, the faces served as a “prime” (something that starts you thinking a particular way) and half the time were of a black person and half the time of a white person. Table 2-8 shows the means and standard deviations for reaction times (time to decide if the picture is of a gun or a tool) after either a black or white prime. (In Experiment 2, participants were told to decide as fast as possible.) (Be sure to explain some specific numbers as well as the general principle of the meanand standard deviation.)
TARGET M SD M SD
Gun 423 64 441 73
Tool 454 57 …
The solution discusses the results in the table in about 200 words. It also discusses the topic of means and standard deviations, and how this relates to the table data.