Many people who quit smoking complain of weight gain. The results of an investigation of the relationship between smoking cessation and weight gain are given in the article “Does Smoking Cessation Lead to Weight Gain?” (American Journal of Public Health [1983]: 1303–1305). Three hundred twenty-two subjects, selected at random from those who successfully participated in a program to quit smoking, were weighed at the beginning of the program and again 1 year later. The mean change in weight was 5.15 lb, and the standard deviation of the weight changes was 11.45 lb. Is there sufficient evidence to conclude that the true mean change in weight is positive? Use α = .05.