Harrell & Harrell wants to predict cell phone expense for the firm's two partners at different levels of minutes used per month. The following data have been gathered for the past 6 months: Month Cell Phone Expense Minutes Used May $330 1,650 June $320 1,450 July $502 2,450 August $456 2,100 September $470 2,340 October $536 2,800 Using the high-low method, compute the incremental cost when the partners phone usage increases by 5,000 minutes? O $750 $888 $868