Harlan Gravity Grips produces spike sets for track shoes. CEO Brittany Harlan has gathered the following information about the company's sales volume and marketing cost for the past six months Sales Volume Total Marketing Costs January 64,500 $8,265 February 48,400 $6.605 March 69,800 $8.420 April 74,600 $8,635 May $8.180 67.300 76,900 June $8,885 (a) Your answer is incorrect Identify the high and low points. Machine Hours High point Low point Using the high-low method compute the variable marketing cost per spike set. (Round unit cost to 2 decimal places, es, 5275.) per spike set sold Variable marketing cost