Mountain Dental Services is a specialized dental practice whose only service is filling cavities. Mountain has recorded the following for the past nine months Number of Month January February Cavities Filled Total Cost 300 $5,000 650 6,050 March 329 5,200 April 475 5,750 May 550 6,050 June 575 6,200 July 600 6,250 August 250 5,100 September 700 6,600 Required: 1. Use the high-low method to estimate total fixed cost and variable cost per cavity filled. 2. Using these estimates, calculate Mountain's total cost for filling 450 cavities...