find total fixed cost

Sheridan Gravity Grips produces spike sets for track shoes. CEO Brittany Sheridan has gathered the following information about the company's sales volume and marketing cost for the past six months: January February March April May June Sales Volume 550.728 390,564 561,284 543,000 546,188 552,552 Total Marketing Costs $82,756 $72,849 $83,092 $82,178 $82,512 $82,876