Please help with 1-15!

This is the rst of 15 questions in this set. Speed of decisions A large company has come up with a new process for making group decisions involving management issues at a certain level. The company is interested in testing whether this new process results in faster decisions than the old process. (Faster decision-making was not the objective of the new process, and no incentive for faster decision-making was adopted as part of the new process. Therefore, the company is not concerned that quality of decisions was sacriced for speed with the new process. In fact, the stated objective of the new process was to reach better decisions.) The company collects the following data on how many minutes it took to arrive at a group decision, based on random samples of decisions using the two processes. Observations from the new process are observations from the X population, and observations from the old process are observations from the Y population. Sample mean Sample Sample Process minutes standard deviation size New (X) 99 25 16 Old (Y) 110 14 25 Assume that decision times are approximately normally distributed in each of the two populations, with a common but unknown variance. The population means are Ux and My, and the population variances are of and or. Estimate the difference between the population means with a 90% confidence interval for My -My. Which of the following is the correct confidence interval? Choose the letter that represents your choice. 1 1 1 1 or c; > 6% (2) Ho: oleoyz 2 1 or 0% 2 6'2, vs. HA: oleoyz