How to break a multiple regression into variable and fixed cost for each item. This is needed to do an Overhead Budget.

How would I get the fixed and variable cost for maintenance and utilities.

I know how to run a multiple regression but I keep getting the intercept to be a negative number.

Silk-Screen Overhead Budget Prepare an overhead budget for each quarter and for the year in total. List the 6 overhead items in the following order: Variable Overhead Costs, including ink, maintenance, utilities, graphics design, and subtotal of variable costs; Fixed Overhead Costs, including rent, maintenance, utilities, graphics design, property taxes and insurance, depreciation, and subtotal of fixed costs; and finally, Total Overhead Costs

and More as below. Ethan will use the regression method to estimate variable and fixed costs for the purpose of budgeting. January February March April May June July August September October November December Shirts Sold 1,800 2,110 2,630 3,250 5,000 5,300 3,920 2,090 8,000 6,810 6,020 Maintenance Cost $1,620 1,720 1,740 1,780 1,912 1,966 1,805 1,705 2,120 2,030 2,014 2,240 Utility Cost $1,100 1,158 1,161 1,211 1,485 1,502 1,278 1,117 1,688 1,630 1,498 1,740 8,700 (Note: When estimating maintenance and utility costs, input data on a worksheet and use Excel functions to estimate the slope and the intercept. When you budget maintenance and utility costs, you should use formulas linked to the estimates of slope and intercept, and related quantity of shirts, instead of inputting numbers by hand. Use Excel to display the total costs to the whole dollar.) and More as below. Ethan will use the regression method to estimate variable and fixed costs for the purpose of budgeting. January February March April May June July August September October November December Shirts Sold 1,800 2,110 2,630 3,250 5,000 5,300 3,920 2,090 8,000 6,810 6,020 Maintenance Cost $1,620 1,720 1,740 1,780 1,912 1,966 1,805 1,705 2,120 2,030 2,014 2,240 Utility Cost $1,100 1,158 1,161 1,211 1,485 1,502 1,278 1,117 1,688 1,630 1,498 1,740 8,700 (Note: When estimating maintenance and utility costs, input data on a worksheet and use Excel functions to estimate the slope and the intercept. When you budget maintenance and utility costs, you should use formulas linked to the estimates of slope and intercept, and related quantity of shirts, instead of inputting numbers by hand. Use Excel to display the total costs to the whole dollar.)