Soru 10 A new method is improved in the medical treatment of an illness. A random sample of 12 patients were chosen and treated with this method. The times of recovery from an illness are found to be as follows: X(days): 10,12, 8, 9, 9, 17, 9, 14, 3, 7, 12, 10 The distribution of the population is known to be normal. Find the 95% confidence interval for the variance of recovery time of this illness. O a. (6.30;36.13) O b. (5.58;45.25) Oc. (5.91;31.36) O d. (5.16;53.08) O e. (7.01;30.20) Seçimimi temizle 210730093141-38592

Suppose that we are interested in comparing the academic success of college students who belong to fraternal organizations and the academic success of those who do not belong to fraternal organizations. Random samples of size 40 are taken from each population where the variances and standard deviations are known. Sample Size Mean GPA Variance (2) 2.03 2.21 Fraternity member (f): 40 Nonmembers (n): 40 .46 .35 Construct a 96% confidence interval estimate for the difference between the mean GPAS (uf- un). Interpret this interval estimate. What can you conclude about the mean GPAs of the two groups?

Do a two-sample test for equality of means assuming unequal variances. Calculate the p-value using Excel. (a-1) Comparison of GPA for randomly chosen college juniors and seniors: x⎯⎯1x¯1 = 4.5, s1 = .20, n1 = 15, x⎯⎯2x¯2 = 4.9, s2 = .30, n2 = 15, α = .025, left-tailed test.(Negative values should be indicated by a minus sign. Round down your d.f. answer to the nearest whole number and other answers to 4 decimal places. Do not use "quick" rules for degrees of freedom.)        d.f. Not attempted t-calculated Not attempted p-value Not attempted t-critical Not attempted    (a-2) Based on the above data choose the correct decision.   Do not reject the null hypothesis Reject the null hypothesis

The results of a state mathematics test for random samples of students taught by two different teachers at the same school are shown below. Can you conclude there is a difference in the mean mathematics test scores for the students of the two teachers?                                                                                                                                                                                                                                                                    Use α = 0.01. In addition, assume the populations are normally distributed and the population variances/standard deviations are not equal.   Teacher 1 Teacher 2 ?̅1 =  473 ?̅2 = 459 S1 = 39.7 S2 = 24.5 n 1 = 8 n 2 = 18   a. State the null and alternate hypotheses (write it mathematically) and write your claim.   b. Find the test statistic        c. Identify the Rejection region (critical region) and fail to reject region. Show this by drawing a curve and…