Compute marginal cost and average cost schedule for firm

Question

Assume that a firm in a perfectly competitive industry has the following total cost schedule

OUTPUT (UNITS)                          TOTAL COST ($)

  10                                               $110

  15                                                150

   20                                               180

   25                                                225

   30                                                300

    35                                               385

   40                                                480

1. Calculate a marginal cost and an average cost schedule for the firm.
2. If the prevailing market price is $17 per unit, how many times will be produced and sold? What are profits per unit? What are total profits?
3. Is the industry in long-run equilibrium at this price?