Sahana is the new manager of a warehouse for Footwear manufacturing in Wollongong. She has been asked to estimate future monthly purchase costs for material no. 344 used in the factory. Sahana's purchase and quantity data for the past nine months are as follows: Month Cost of purchase $12 675 January February March Quantity purchased 2 710 metres 2 810 13 000 17 653 4153 3 756 April 15 825 13 125 May 2 912 June 13 814 3387 July 15 300 3622 2 298 August September 10 233 14 950 3 562 Estimated monthly purchases for this material, based on expected demand of products for the rest of the year, are: Month Purchase quantity expected October November December 3 340 metres 3710 metres 3040 metres Required a) The computer in Sahana's office is down, so you are asked to help her to 15 marks prepare a cost function to estimate the future purchase cost for material no. 344 using the high-low method. b) Using the equation from requirement 1, calculate the future expected 10 marks purchase costs for each of the last three months of the year ) c) After a few hours the computer is fixed and you can use it to determine 25 marks the cost function using regression method to estimate future purchase cost for material 344 and obtain the cost function: y = $2 582.57 + 3.54x. Using the regression results, calculate the expected purchase costs for October November and December. Compare the expected purchase costs with the expected purchase costs calculated using the high-low method in requirement b. Comment on your results