The McGraw 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: $($CMA adapted$)$

$\backslash$table$[[,\backslash$table$[[$Hours of$],[$Activity$]],\backslash$table$[[$Maintenance$],[$Costs$]]],[$January$,450,$$$4,500$