1 2 3 4 Many diabetics today are using insulin pumps to release small amounts of insulin as needed in order to improve their health. Insulin pumps tend to keep glucose levels in the bloodstream at a more constant level. Suppose that a study is planned to compare Group A whose members use insulin pumps to Group B whose members use the traditional method of injections. The sample from Group A will consist of 20 individuals and the sample from Group B will consist of 40 individuals. The samples will be independent and random from populations with equal variances. Select the correct formula for a confidence interval which would be used to compare the mean glucose levels in the bloodstreams of the members of the two populations. Condence Interval for )A1 - [A2 _ _ 2 2 1_(x1x2)+z s1 s2 Independent Samples "1 "2 ASSUME EQUAL no MENTION or Population Variances Population Variances _ _ 2 2 2 2 03(X1-x2):t 32(n1 nL) 71'0'2 Assumeaqaetrz 1 2 df: "1-!- n2 2 (n1 -1)s3+(nz-1)s: 9' n1+n22 df= n1+n2 '2 52: ("1-1)s3+(n2-1)s n1-i-n2 -2 _ _ 2 2 @ 4-(x1lett :1 . 1 n1 n2 lf samples are small then assume df= "1+ n2 _ 2 normally distributed population(s). (\"1:"2l