Refer to Exhibit 22-7. The average total cost (ATC) of producing 4 units of output is Exhibit 22-7 Output Total Cost 0 $30 1 $40 2 $60 3 $90 4 $110 5 $125 6 $135 7 $140 Question 19 options: a) $27.50 b) $11.25 c) $5.00 d) $3.50