Motivation of drug dealers. Refer to the Applied Psychology in Criminal Justice (Sept. 2009) study of convicted drug dealers’ motivations, Exercise 2.102 (p. 105).

Recall that the sample of drug dealers had a mean Wanting Recognition (WR) score of 39 points, with a standard deviation of 6 points.

a. Find and interpret the z-score for a drug dealer with a WR score of 30 points.

b. What proportion of the sampled drug dealers had WR scores below 39 points? (Assume the distribution of WR scores is mound shaped and symmetric.)