In the problem of estimating total hospitalization costs for kidney stone patients, suppose Muscat and Dhofar regions were selected as strata because they have very different incident rates for the disease, and the estimates for each region was needed separately. Also, this stratification into geographic regions simplified the sampling procedures. The sample data are summarized as follows: Dhofar 1,260 n,"150 Mean cost :-170 RO Mcan cost: -125 RO Muscat -3050 0-745 C,-10 RO ", -2525 6, 680 C-12 RO A previous study showed the number of kidney stone incidents in the Muscat to be 325 out of 100,000 population and the number in the Dhofar to be 320 out of 100,000. The population of the Muscat was 775,878, and the population of the Dhofar was 249,729, according to the 2010 census. a) Obtain the estimates of N, and N, the numbers of kidney stone patients expected to be found in the Muscat and Dhofar regions. b) Obtain the average annual cost of hospitalization of the kidney patients of the two region combined with 95% confidence interval and interpret the results.