Based on the table below, what is the profit maximizing level of output for the monopoly firm assuming that the firm is earning a positive economic profit?

Price                 Quantity                     Marginal Cost

  $15                   1000                             $3

    14                   2000                               4

    13                   3000                               5

    12                   4000                               6

    11                   5000                               7

    10                   6000                               8