At Hulk Hospital, the cost of ultrasounds has a fixed component and a variable component related to the number of ultrasounds taken. The cost and number of ulrasounds taken at the hospital for the past seven months are provided below: Number of Ultrasounds taken Cost of Ultrasounds March 650 $2,700 April 700 $2,850 May 500 $2,250 June 420 $1,750 July 460 $2,000 August 300 $1,270 September 350 $1,500 Using the high-low method, determine a formula for calculating ultrasound costs in a given month. b) What would be the expected ultrasound cost incurred for a month in which 585 X-rays are taken