I am only missing one number here, the box under both December sales and # of units.

I have tried 15, 30, 45, 10, and 20 but they were all incorrect values.

so what value would be correct?

Check my work Part 2 of 2 Required Information Trey Monson starts a merchandising business on December 1 and enters into three inventory purchases 071 Purchases on December 7 Purchases on December 14 Purchases on December 21 10 units @ $ 6.00 cost 20 units $12.00 cost 15 units $14.00 cost Book Required: Monson sells 15 units for $20 each on December 15. Assume the periodic Inventory system is used. Determine the costs assigned to ending Inventory when costs are assigned based on the weighted average method. (Amounts to be deducted should be indicated with a minus sign. Round cost per units to 2 decimals.) Periodic Weighted Average Inventory on hand Cost per Inventory of units unit Value 101 5 6 .00 $ 20 12.00 240 Cost of Goods Sold of units Avg.Cost per Cost of Sold unit Goods Sold | 00 References Purchase - December 7 Purchase - December 14 Purchase - December 21 Available for Sale December Sales Total