Answer:
We generally calculate total average cost by dividing total cost / total output units.
In this case, we are not given the output units, but instead we are given the output value, so we should find a percentage from total revenue.
total costs = $4,800,000
total revenue = $20,000,000 + $5,000,000 = $25,000,000
average total cost = ($4,800,000 / $25,000,000) x 100 = 19.2%
This means that for every $100 of revenue, the merged company will spend $19.20.