The following information is available:

Units in process, Sept. 1 (60 percent converted)4,000 units

Units in process, Sept. 30 (30 percent converted)2,000 units

Units started during the month 15,000 units

Materials are added at the beginning of the process.

How many equivalent units in process for conversion were there in September using the weighted average method?

18,000

15,200

17,600

16,400