I ne accounting department of insecurity Protection Services, a company that provides security services for rich, famous, and insecure people is analyzing the costs of its accounting services. Analysts have selected the following cost drivers: customer accounts maintained, and number of paychecks processed. The cost data and cost drivers for 16 months follow: Month Cust accts Paychecks Costs (S) 325 1029 64000 310 993 69100 302 1268 64200 213 1028 61500 222 984 61800 213.9 712 51000 131 762 51220 123 739 54500 115 708 50700 296 1232 65100 213 978 58300 222 929 57800 217 1059 62500 942 55200 1299 71830 1283 65100 1 21 3 4 5 6 71 8 9 10 11 12 13 14 15 16 132.4 300 315 (a) Using regression analysis, find the best cost estimation equation. (b) Estimate the accounting department's costs of doing business based on 1,000 pay checks processed and 200 customer accounts maintained.