Month Miles Driven 15,500 17,500 14,400 January ...... February March April May .... June July Van Operating Costs $5,400 $5,350 $4,980 $5,280 $5,580 16,400 16,900 15,300 $5,010 $4,590 13,500 Kerri Rafferty, owner of Flower Hour, operates a local chain of floral shops. Each shop has its own delivery van. Instead of charging a flat delivery fee, Rafferty wants to set the delivery fee based on the distance driven to deliver the flowers. Rafferty wants to separate the fixed and variable portions of her van operating costs so that she has better idea how delivery distance affects these costs. She has the following data from the past seven months: Click the icon to view the data.) Use the high-low method to determine Flower Hour's cost equation for van operating costs. Use your results to predict van operating costs at a volume of 14,500 miles. C. Let's begin by determining the formula that is used calculate the variable cost (slope). Variable cost (slope)