Method of Least Squares Sophia operates a full service day spa in a small college town. Recently, Sophia rented space next to her spa and opened a spray tanning salon. She anticipated that the costs for the spray tanning service would primarily be fixed, but found that tanning salon costs increased with the number of appointments. Costs for this service over the past 8 months are as follows: Month January February March April May June July August Tanning Appointments 1,500 1,600 1,700 1,400 1,300 1,625 1,350 1,200 Total Cost $36,900 38,250 39,000 33,750 36,000 40,000 35,100 33,000

Sophia operates a full service day spa in a small college town. Recently, Sophia rented space next to her spa and opened a spray tanning salon. She anticipated that the costs for the spray tanning service would primarily be fixed, but found that tanning salon costs increasad with the number of appointments, Costs for this service over the past 8 mooths are as follows: 1. Using a computer spreadsheet program such as Excel, run a regression on these data. Based on the regression output, select the cost formula for tanning. Roun the fixed cost to the nearest dollar and the variable rate to the nearest cent. 2. Using the computed formula, what is the gredicted cost of tanning services for September for 1,550 appointments? Round to the nearest dollar