Independent random samples from two regions in the same area gave the following chemical measurements (ppm). Assume the population distributions of the chemical are mound-shaped and symmetric for these two regions. Region I: x1; 71=12 981 726 686 496 657 627 815 504 950 605 570 520 Region II: x2; 12 =16 1024 830 526 502 539 373 888 685 868 1093 1132 792 1081 722 1092 844 Let u, = 678 be the population mean and 1= 164 be the population standard deviation for x1. Let U2 = 812 be the population mean and 2= 239 be the population standard deviation for X2. Determine and examine the 90% confidence interval for H1 - H2. Does the interval consist of numbers that are all positive? all negative? or different signs? At the 90% level of confidence, is one region more interesting that the other from a geochemical perspective