Erin Hamill is the owner operator of a tanning salon. She is considering four price levels for a weekly tanning pass. Her estimate of price and quantity demanded are:
Price Quantity Demanded
$12.00 ........ 330
$11.00 ........ 380
$10.00 ........ 390
$ 9.00 ........ 430
Monthly costs of providing the tanning service include $1,500 of fixed costs and variable costs of $2.50 per service.

Required
Which price will yield the largest monthly profit?