Answer: 5,882.5 hours
Explanation:
Cumulative Labor Hours to be planned for = Cumulative factor * Time of first unit
Cumulative Factor = Average learning rate for Number of units.
Learning rate from unit 1 to 2 = Labor hours required for 2nd unit / Labor Units required for 1st unit
= 2,250/2,500
= 0.9
Learning rate from unit 2 to 3 = Labor hours required for 3rd unit / Labor Units required for 2nd unit
= 2,120/2,250
= 0.94
Average learning rate = (0.9 + 0.94) / 2
= 0.9
= 90%
There are 6 units in total including the first units checked and the additional 3 units.
Cumulative factor for 6 units at 90% from the table is 5.101.
Cumulative labor hours = 5.101 * 2,500
= 12,752.5 hours
The time for the Addiotnal 3 units is;
= Cumulative time for all units - time for the first 3 units
= 12,752.5 - 2,500 - 2,250 - 2,120
= 5,882.5 hours