Manufacturing and product development a a typical washing machine has several different cycles, including soak, wash, and rinse. the energy consumption of a washing machine is linked to the length of each cycle. a random sample of 21 washing machines was obtained, and the length (in minutes) of each wash cycle was recorded. the summary statistics are x 37.8 and cycle times is normal. a. find a 90% confidence interval for the true mean wash cycle time. write a solution trail for this problem