C20 X Y fx A B C D E F G H K L M N O P Q R 1 Patient# Cream 1 Cream 2 Diff (1-2) 2 1 16 14 Q4. (11 marks) Two creams are available by prescription 3 AWN IN 4 for treating moderate skin burns. A study to compare the A) Answer 4 10 10 effectiveness of the two creams is conducted using 15 7 randomly chosen patients with moderate burns on their 4 arms. Two spots of the same size and degree of burn are 6 5 5 marked on each patient's arm. One of the creams is 10 12 selected at random and applied to the first spot, while 5 the remaining spot is treated with the other cream. The B) Answer 6 number of days until the burn has healed is recorded for 10 19 23 each spot. The data are shown below. 10 10 12 11 12 12 a) Is this sampling method dependent or independent? b) State the null and alternate hypotheses to test C) Answer 13 12 9 7 whether the two creams are equally effective (i.e., take 14 13 10 11 the same average time to heal the burn). H 15 14 20 24 c) Hand calculate the test statistic. Show your calculation. 16 15 12 10 d) Run the test in Excel/Excel template. Show output. 17 What is the p-value for the test? Use the 5% significance 18 level. Show the Excel outputs. D) Answer e) What are the assumptions for this test? Are the t-value = 19 p-value = 20 assumptions met? draw boxplot and probability plot to 21 check if the assumptions being met. f) Based on the p-value, interpret the results of this test. 22 g) Hand calculate the 95% confidence interval for the 23 difference between the two creams. Obtain Excel output E) Answer 24 to confirm your results. 25 h) Does your 95% CI confirms your hypothesis test 26 conclusion? Explain. 27 28 F) Answer 29