To solve this problem using the weighted average method, we need to calculate several key figures:

Part A: Number of Units in Work in Process (WIP) at the End of the Month

Given that 89,400 units were transferred out, and there were 17,200 units in the beginning WIP, we can calculate the ending WIP as follows:

• Total units to account for: $\text{Units in beginning WIP} + \text{Units started} = \text{Units transferred out} + \text{Ending WIP units}$ $17,200 + 84,300 = 89,400 + \text{Ending WIP units}$ $101,500 = 89,400 + \text{Ending WIP units}$ $\text{Ending WIP units} = 101,500 - 89,400 = 12,100 \text{ units}$ This confirms the ending WIP is 12,100 units.

Part B: Units to be Accounted for, Assigned Costs, and Equivalent Units of Production

1. Whole Units to be Accounted for:

   This includes units in the beginning WIP and the units started during May: $\text{Whole units to be accounted for} = 17,200 (\text{Beginning WIP}) + 84,300 (\text{Started}) = 101,500 \text{ units}$

2. Whole Units to be Assigned Costs:

   Since the weighted average method considers the total units (beginning + started), the whole units to be assigned costs will also be: $101,500 \text{ units}$

3. Equivalent Units of Production (EUP):

   The equivalent units of production consider the completion percentages:

   • Units completed and transferred out: 89,400 units (since they are fully completed, they contribute fully to the EUP)
   • Ending WIP units: 12,100 units at 35% completion contribute to EUP
   • For direct materials, which are usually added at the start, 12,100 units contribute fully.

   Therefore: $\text{EUP for materials} = 89,400 + 12,100 \times 100\% = 101,500 \text{ units}$ $\text{EUP for conversion costs} = 89,400 + 12,100 \times 35\% = 89,400 + 4,235 = 93,635 \text{ units}$

Answers:

1. Whole units to be accounted for: 101,500 units
2. Whole units to be assigned costs: 101,500 units
3. Equivalent units of production: 93,635 units for conversion costs

Additional Questions:

1. How do the equivalent units of production differ for materials versus conversion costs?
2. What would change if the beginning WIP was at a different completion percentage?
3. How does the weighted average method affect cost per unit compared to FIFO?
4. If direct materials were added at the end of production, how would this affect the EUP?
5. How would a higher completion percentage of ending WIP affect the equivalent units of production?

Tip: Always remember to carefully distinguish between materials and conversion costs when calculating equivalent units of production.