Kamloops Laboratory Services (KLS) Inc. performs a variety of test for local private and public health organizations. The lab has incurred the following costs over the past year: Costs Month January February March April May June July August September October November December Number of test 3,050 4,500 7,100 7,000 4,700 5,900 6,000 6,100 5,300 4,900 4,800 5,050 $61,000 74,500 95,600 99,000 74,800 89,000 91,000 90,000 87,000 76,200 78,100 80,700 Required: a. Using the high-low method, write a cost formula to express the cost behaviour of KLS's production costs. b. If KLS's believes that it will perform 7,500 tests next month, what is the predicted costs that the company will incur using the high-low method? c. Briefly comment on the adequacy of the high-low method in determining cost behaviour