Department K had 3,000 units 45% completed in process at the beginning of the period, 17,000 units completed during the period, and 1,200 units 40% completed at the end of the period. What was the number of equivalent units of production for the period for conversion if the first-in, first-out method is used to cost inventories? Assume the completion percentage applies to both direct materials and conversion cost.

A) 18,350
B) 16,310
C) 15,650
D) 16,130

To calculate the equivalent units of production for conversion, we need to add the equivalent units of beginning work in process, units completed during the period, and equivalent units of ending work in process.

Equivalent units of beginning work in process = number of units * percentage completion = 3,000 * 0.45 = 1,350
Equivalent units of ending work in process = number of units * percentage completion = 1,200 * 0.40 = 480
Equivalent units of production = 1,350 + 17,000 + 480 = 18,830

However, we are using the first-in, first-out method, which means we need to subtract the equivalent units of beginning work in process that were completed during the period (since they were already partially completed from a previous period).

Equivalent units of beginning work in process completed during the period = number of units * percentage completion = 3,000 * 0.45 = 1,350
Adjusted equivalent units of production = 18,830 - 1,350 = 17,480

Therefore, the answer is D) 16,130.