Gastineau Tile Installation Corporation measures its activity in terms of square feet of tile installed. Last month, the budgeted level of activity was 1, 230 square feet and the actual level of activity was 1, 200 square feet. The company's owner budgets for supply costs, a variable cost, at $2.70 per square foot. The actual supply cost last month was $2, 690. In the company's performance report for last month, what would have been the spending variance for supply costs? $67 F $550 F $631F $81 F