1. Fish Oil and Blood Pressure. Find the 95% confidence interval and one-sided p-value asked for in Exercise 13(e) and (g) but use a statistical computer package to do so.
2. Auto Exhaust and Lead Concentration in Blood. Researchers took independent random samples from two populations of police officers and measured the level of lead concentration in their blood. The sample of 126 police officers subjected to constant inhalation of automobile exhaust fumes in downtown Cairo had an average blood level concentration of 29.2 !g/dl and an SD of 7.5 !g/dl; a control sample of 50 police officers from the Cairo suburb of Abbasia, with no history of exposure, had an average blood level concentration of 18.2 !g/dl and an SD of 5.8 !g/dl. (Data from A.-A. M. Kamal, S. E. Eldamaty, and R. Faris, "Blood Lead Level of Cairo Traffic Policemen," Science of the TotalEnvironment 105(1991): 165-70.) Is there convincing evidence of a difference in the population averages?