Required information [The following information applies to the questions displayed below.] Nation's Capital Fitness, Inc., operates a chain of fitness centers in the Washington, D.C., area. The firm's controller is accumulating data to be used in preparing its annual profit plan for the coming year. The cost behavior pattern of the firm's equipment maintenance costs must be determined. The accounting staff has suggested the use of the high-low method to develop an equation, in the form of Y= a + bx, for maintenance costs. Data regarding the maintenance hours and costs for last year are as follows: Month January Hours of Maintenance Service 530 Maintenance Costs $ 5,237 February 460 4,190 March 260 2,780 April 490 4,340 May 360 3,000 June 440 4,140 July 360 3,020 August 430 3,600 September 450 3,980 October 380 3,250 November 370 3,170 December 350 3,060 Total 4,880 $43,767 Average 407* $ 3,647* *Rounded 3. Compute the predicted maintenance cost at 640 hours of activity. Maintenance cost