Answer:
(a) Total units for January = 14,200
Total units for May = 23,260
(b). Conversion cost for :
January = 13,053  
March = 13,660
May = 21,688
July = 11,212
Explanation:
As per the data given in the question,
1)
                                                  Jan.                        May
Units to be accounted for
Beginning WIP                            0                            0
Started into production            14,200                   23,260
Total number units                   14,200                   23,260
Units accounted for 
Transferred out                         11,100                   15,400
Ending WIP                                 3,100                      7,860
Total units                                 14200                   15400
2)
We can calculate the conversion cost by using following formula:
Conversion cost = Transferred out unit + (Work in process  unit × conversion cost)
                             Material           Conversion cost
Jan.                       14,200                    13,053              (11,100 + 3,100 × 63%)
Mar.                      15,700                     13,660              (12,300 + 3,400 × 40%)
May                       23,260                   21,688              (15,400 + 7,860 × 80%)
July                        12,400                   11,212              (10,200 + 2,200 × 46%)