a. A designer estimates that she can increase the average time between failures of a part by 5 percent at a cost of $450. Currently, the average time between failures is 100 hours and the average repair time is 4 hours. (Round your "Availability" answer to 4 decimal places.) b. A designer estimates that she can reduce the average repair time by 10 percent at a cost of $200. Currently, the average time between failures is 100 hours and the average repair time is 4 hours. (Round your "MTR" answer to 2 decimal places and "Availability" answer to 4 decimal places.) c. Which option would be more cost-effective? Thus, the designer should choose method