Hey! Need help with this :) thanks

Brian Snow is a river guide on the Columbia River. Typically bran takes tourists around 30 to 80 miles upriver. Round trip takes anywhere from 2 to 8 hours before returning to dock. Brian has noted that overall fuel costs vary based on "miles upriver" and he is considering changing his guide fee to separately charge customers for estimated fuel costs. Below Brians log for 15 typical days showing "miles upriver" and "total fuel cost". Use the high-low method to determine the "fixed fuel cost" associated with the trolling time, and the "variable fuel cost" associated with running up and down the river. If the sole objective of the fuel charge is to approximately recover actual costs incurred each day, would "$2.50 per mile upriver" be a fair formula? What alternative formula might you suggest