Serendipity Manufacturing implemented lean manufacturing in its Wheeling plant as a pilot program. During the most recent three weeks, the following data pertaining to a specific product line value stream was collected:

Week $1$:

Sales $=500$ units @ $$50$ per unit selling price

Beginning inventory $=80$ units @ $$15($$$5$ materials, $$10$ conversion$)$

Production $=500$ units @ $$15($$$5$ materials, $$10$ conversion$)$

Week $2$:

Sales $=675$ units at $$50$ per unit selling price

Beginning inventory $=80$ units at $$15($$$5$ materials, $$10$ conversion$)$

Production $=595$ units at $$15($$$5$ materials, $$10$ conversion$)$

Week $3$:

Sales $=650$ units at $$50$ per unit selling price

Beginning Inventory $=0$

Production $=700$ units at $$15($$$5$ materials, $$10$ conversion$)$

Required:

a$.$ Prepare a traditional income statement for each week.

b$.$ Calculate the average value stream product cost for each week. What does this cost signal, if anything?

c$.$ Prepare a value stream income statement for each week. Assume that any increase in inventory is valued at average cost. Comment on the financial performance of the value stream and its relationship to traditional income measurement.