If I have this expenses:
telephone $50 fixed
utilities $260 fixed (25% for the garage and 75% for the house
advertising $75 fixed
insurance $80 fixed
materials $7,500 variable (for 5 computers)
labor $1,800: ($1,300 fixed plus $500 for hours assembling computers)
How a can compute the TOTAL COST FUNCTION and the TOTAL COST FOR THE MONTH?