The Armer Company is accumulating data to be used in preparing its annual profit plan for the coming year. The cost behavior pattern of the maintenance costs must be determined. The accounting staff has suggested that linear regression be employed to derive an equation in the form of y = a + bx for maintenance costs. Data regarding the maintenance hours and costs for last year and the results of the regression analysis are as follows:

Hours of Activity Maintenance Costs

January 500 hrs $ 4,100 cost

February 330 3,200

March 390 3,300

April 280 2,990

May 500 4,280

June 290 2,930

July 310 2,970

August 510 4,420

September 470 4,320

October 470 3,900

November 360 3,500

December 330 3,010

Sum 4,740 42,920

Average 395 3,577

A coefficient 1,062.99

B coefficient 6.3637

Standard error of the a cofficient 220.501

Standard error of the a cofficient 0.54560

Standard error of the estimate 161.575

R2 0.93153

T-value a 4.821

T-value b 11.664

What would be the cost equation if the high-low method is used?