The first unit of a product took 80 work days. The learning curve is estimated to be 90%. The time for the fourth unit will be about __________ work days and the time for the first four units will be about __________ work days.
A) 51; 250
B) 250; 51
C) 65; 285
D) 51; cannot be determined
E) 65; cannot be determined

Question

Quizplus · Accepted Answer

Using the learning curve formula:

Time for nth unit = a * n^b

where a = time for the first unit, b = log(learning rate) / log(2)

Time for fourth unit = 80 * 4^log(0.9)/log(2) = 65.05 work days (rounded to nearest hundredth)

Time for first four units = time for first unit + time for second unit + time for third unit + time for fourth unit

Time for first four units = 80 + 80*0.9 + 80*(0.9)^2 + 65.05

Time for first four units = 285.05 work days (rounded to nearest hundredth)

Therefore, the best choice is C.

The First Unit of a Product Took 80 Work Days