Inspection costs at one of Krivanek Corporations factories are listed below:

January units produced 630 & inspection cost $8,850. February units produced 615 & in $8,819. March 602 units produced & inspection cost $8,760. April 595 unit produced & $8,743 inspection cost. May 688 units produced & $9,036. June 626 units produced & 8,866 inspection costs. July 646 units produced & $8,920 inspection cost. August 670 units produced & $8,977 inspection cost. September 678 units produced & $ 9,013 inspection costs. Management believes that inspection cost is a mixed cost that depends on units produced. Using the high-low, the estimate of the fixed component of inspection cost per month is closest to: ? (show your work please)