Company Y is a monopoly industry. Its contribution margin is estimated at 20% (P-MC)/P = 0.2). From past experience, the owner has determined the following relationship exists between expenditures on advertising and total sales:
Advertising /sales Revenues
$0/$124,000
$5,000/$130,000
$6,000/$135,000
$7,000/$139,000
$8,000/$142,000
$9,000/$144,000
$10,000/$145,000
$11,000/$145,000
What is the optimal level of advertising?