Answer:
Fixed Cost:
Process A = $165,000
Process B = $190,000
VC per unit:
Process A = $5
Process B = $4
TC = FC + VC*Q
Total cost function for Process A
TC(A) = 165,000 + 5Q
Total cost function for Process B
TC(B) = 190,000 + 4Q
We equate the two function
165,000 + 5Q = 190,000 + 4Q
5Q - 4Q = 190,000 - 165,000
Q = 25,000
25,000 units is the indifference level of production.
As process A has lower fixed cost, it is better process if the production volume is lower than 25,000 units. For more than 25,000 units, process B is better.
Purchase from vendor option is better if the production volume is less than 47,500 units [$190,000/$8-$4].