As the purchasing agent of your company you are deciding what type of Xerox machine to buy for your company. You have narrowed your choices to brand X and brand Y. Which have been recommended to you by two friends. Your selection criteria is durability. Your first friend tells you that the 8 brand x machines in her company have an average life-time of 200 days, with a standard deviation of 9 days. Your other friend tells you that the average life-time of the 6 machines in her company is 210 days with a standard deviation of 6 days. Which machine would you pick?