Answer:
Average total cost = $39
Marginal revenue = $32 per unit
Explanation:
The computation of average total cost and marginal revenue is shown below:-
Average total cost = Selling price - (Economic profit ÷ Weekly output)
               = $42 - ($1,500 ÷ 500)
               = $42 - 3
               = $39
Marginal revenue = Marginal cost
So,
Marginal revenue = $32 per unit
Therefore for computing the average total cost and marginal revenue we simply applied the above formula.