Consider a study of drug dealers and their motivation for participating in the illegal drug market (Applied Psychology in Criminal Justice, September 2009). The sample consisted of 100 convicted drug dealers who attended a court-mandated counseling program. Each dealer was scored on the Wanting Recognition (WR) Scale, which provides a quantitative measure of a person's level of need for approval and sensitivity to social situations. (Higher scores indicate a greater need for approval.) The sample of drug dealers had a mean WR score of 39, with a standard deviation of 6. Assume the distribution of WR scores for drug dealers is mound shaped and symmetric.
a. Give a range of WR scores that will contain about 95% of the scores in the drug dealer sample.
b. What proportion of the drug dealers had WR scores above 51?
c. Give a range of WR sores that contain nearly all the scores in the drug dealer sample.