GRB Co. recorded the following cost data for the first four months of 2021. The data applies to its product BAC January units produced equal 640 and total cost equaled $12.240: February units produced equal 583 and total cost equals $12.185) March units produced equal 832 and total cost equaled $13.632: April units produced equal 750 and total cost equaled $12.605. What is the difference between the high total costs and the low total costs for the high and low data points