Harold's Picture manufactures various picture frames. Each new employee takes 6 hours to make the first picture frame and 4.8 hours to make the second. The manufacturing overhead charge per hour is $25. Required: a. What is the learning-curve percentage, assuming the cumulative average method? b. What is the time needed to build 8 picture frames by a new employee using the cumulative average-time method? You may use an index of -0.1520 . c. What is the time needed to produce the 16th frame by a new employee using the incremental unit-time method? You may use an index of -0.3219 . d. How much manufacturing overhead would be charged to the 16 picture frames using the average-time approach