P52.-LO.4 & LO.8 (Appendix; least squares regression) Bon Voyage provides charter cruises in the eastern Caribbean. Tina Louise, the owner, wants to understand how her labor costs change per month. She recognizes that the cost is neither strictly fixed nor strictly variable. She has gathered the following information and has identified two potential predictive bases, number of charters and gross receipts: Month Labor Costs Number of Charters Gross Receipts ($000) January $7,000 9 $11 February 8,200 13 17 March 13,000 22 27 April 13,200 27 35 May 18,500 40 60 June 28,000 62 82 July 33,000 90 110 August 39,000 80 100 September 25,000 80 100 Using the least squares method, develop a labor cost formula using a. Number of charters b. Gross receipts