A time standard was set as 020 hour per unit based on the 50

A time standard was set as 0.20 hour per unit based on the 50th unit produced. Assume the task has a 90 percent learning curve. Refer to Exhibit 4A.5. What would be the expected time of the 100th, 200th, and 400th units? (Round your answers to 2 decimal places.)

I know this question has been posted before, but they both have incorrect answers.

I have found the correct answers but would like to understand and to calculate them using the learning curve table.

100 units @ 90% = .4966
200 units @ 90% = .4469
400 units @ 90% = .4022

The correct answers are

100th = .18 200th=.16 400th=.15   

How do I calculate it to get those correct answers?

Solution

The standard time taken is reduced at 90% because of the learning curve. It means that the labor performing the task will do the task with 90% of the time. So we get

100 units at 90% of 0.20 hour per unit = 0.9 x 0.2 = 0.18 hour per unit

200 units at 90% of 0.18 hour per unit = 0.18 x 0.9 = 0.162 = 0.16 hour per unit

400 units at 90% of 0.162 hour per unit = 0.162 x 0.9 = 0.1458 = 0.15 hour per unit