Recall that a sample of % college students was shown a video of a simulated theft, then asked to select a mug shot that most closely resembled the thief. The students were randomly assigned to view either 3, 6, or 12 mug shots at a time, with 32 students in each group. The number of students in the 3-, 6-, and 12-photos-per-page groups who selected the target mug shot were 19, 19, and 15, respectively.
a. For each photo group, compute the proportion of students who selected the target mug shot. Which group yielded the lowest proportion?
b. Create a contingency table for these data, with photo group in the rows and whether or not the target mug shot was selected in the columns.
c. Analyze the contingency table, part b. Are there differences in the proportions who selected the target mug shot among the three photo groups? Test using α = .10.
For Information: Refer to the Applied Psychology in Criminal Justice (April 2010) study of mug shot choices by eyewitnesses to a crime. Exercise 9.78.