After graduating from dental school two years ago, Dr. Margaret Moore 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 In January of this year, she had to replace the outdated autoclave equipment she inherited from the previous dentist.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: Number of instruments used 850 750 920 Month January February March April May June July August 950 Total autoclave cost $6,855 6,250 7,319 7,760 8,570 7,258 8,465 7,711 1,150 900 1,050 975 Identify the high and low points. The highest number of instrument is 1150 and the highest total autoclave cost is 8570 The lowest number of instrument is 750 and the lowest total autoclave cost is 6250 High point $ $ Low point 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.) $ $ 5.80 Variable cost per instrument