49. The director of Human Resources at a large company wishes to determine if newly instituted training has been effective in reducing work-related injuries. In a random sample of 100 employees taken from the six months before this training began (group 1), she found 15 had suffered a workrelated injury. Using a random sample of 150 employees from the six months since the training began (group 2), she found 12 had suffered a work-related injury. The 99% large sample condence interval estimate of the difference in population proportions, p1 p2, is: - (-0.028, 0.168). (-0.038, 0.178). (-0.012, 0.152). (-0.006, 0.030)