2.8 and 2.9 go together and I can't figure this out for some reason, thank you I really appreciate it!!

Required a. What effect would this change in accounting quantity have on the total fixed infrastructure cost of the 737 Next-Generation plane? b. What effect would this change in accounting quantity have on the unit cost of the 737 Next- Generation plane? 2.8 (LO 2) Scattergraphs Stratton, Inc., has collected the following information on its cost of electricity: Machine Total Hours Electricity Costs January 510 $240 February 540 $300 March 360 $205 April 450 $215 May 660 $290 June 690 $300 July 340 $180 August 520 $260 September 240 $120 October 750 $340 November 840 $360 December 600 $320 End-of-Chapter Required a. Prepare a scattergraph of Stratton's electricity costs for the year. Plot the total electricity cost on the y-axis. Draw a line that you think best represents the electricity cost function. Be sure that the line runs through at least one of the data points. b. What is the equation of the line you drew in part (a)? c. What is the expected electricity cost when 750 machine hours are used? d. Why does your answer to part (c) differ from the actual cost for the month of October, when 750 machine hours were used? 2.9 (LO 2) High-low method Refer to the data in Exercise 2-8. Required a. Using the high-low method, compute the variable cost of electricity per machine hour. b. Compute the total fixed cost of electricity. c. Represent the electricity cost function in equation form. d. What is the expected electricity cost when 750 machine hours are used? e. Why does your answer to part (d) differ from the actual cost for the month of October, when 750 machine hours were used? 2.10 (LO 2) High-low method 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 In January of this year she had to replace the outdated autoclave equipment she inherited from the previous dentist.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 prepar- ing her budget for next year, she is concerned about understanding how her cost for sterilizing her dental changed. She has gathered the following information from her records