question 4

(Questions 4 - 8) You've collected random samples of 12 oz. cups of coffee from both Starbucks and Dunkin Donuts. Assume the caffeine content in coffee is normally distributed in the population. Here is the caffeine content in each cup (in mg): -------- Dunkin Donuts 120 134 127 119 135 132 128 127.86 6.41 Starbucks l 110 105 101 113 103 105 101 105.43' 4.54 You wish to determine if there is a difference between the two coffee makers in their caffeine content. Perform the appropriate test to answer this question. Use a t-critical of 2.25. What is the null hypothesis for this test? What is the test statistic value? What are the degrees of freedom? What is your conclusion? Compute the 95% (t-critical of 2.25) confidence interval for this test. Type the upper value. (Does it confirm or refute your conclusion?) WNP'SJ'P