13. Downs and Abwender (2002) evaluated soccer players and swimmers to determine whether the routine blows to the head experienced by soccer players produced long-term neurological deficits. In the study, neurological tests were administered to mature soccer players and swimmers and the results indicated significant differences. In a similar study, a researcher tests a sample of n = 16 soccer players and obtains an average score of M = 73 with SS = 1480. A sample of n = 12 swimmers produces M = 84 with SS = 1016.

a. Make a point estimate of the mean difference in neurological test score between the two populations of athletes represented by the two samples.

b. Compute a 90% confidence interval to estimate the population mean difference.