a) The average product of fertilizer when 4 tons are used is AP=TP/Q=2200/4=550.AP = TP/Q = 2200/4 = 550.AP=TP/Q=2200/4=550.
e) The efficient level of output it must produce at is 2600 with 5 tons used, because if 6 tons are used, the total product will decrease.