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