Need help with part D with the given information.

After graduating from dental school two years ago, Dr. Lauren Farish purchased the dental practice of a long-time dentist who was retiring. In January of this year, she had to replace the outdated autoclave equipment she inherited from the previous dentist. Now, as she is preparing her budget for next year, she is concerned about understanding how her cost for sterilizing her dental instruments has changed. She has gathered the following information from her records: Month Number of instruments used Total autoclave cost January 850 $ 7,600 February 750 6,800 March 920 8,200 April 950 8,600 May 1,150 9,900 June 900 8,100 July 1,050 9,600 August 975 8,700 (a) Your answer is correct. Identify the high and low points. Activity Level High point 1,150 $ 9,900 Low point 750 6,800 Using the high-low method, what is the variable cost of sterilizing an instrument using the new equipment? (Round answer to 2 decimal places, e.g. 52.75.) $ 7.75 Variable cost per instrument What is the fixed cost of the autoclave equipment? (Round answer to 2 decimal places, e.g. 52.75.) $ 987.5 Fixed cost e Textbook and Media Attempts: 1 of 4 u (c) Your answer is correct. What is the cost formula that Dr. Farish should use for estimating autoclave sterilization costs for next year's budget? Formula of total cost ($ 7.75 x # of instruments) + $ 987.50 (d) Your answer is incorrect. If Dr. Farish estimates she will use 900 instruments next month, what cost should she include in her budget for instrument sterilization? (Round answer to 2 decimal places, e.g. 52.75.) $ Total cost