Joey Bag-o-donuts owns an ice cream shop. Looking at last year's utility bills, the highest utility bill was $4000 for 2000 machine hours. The lowest utility bill was $2500 for 1200 machine hours. ...

Calculate the variable rate per machine hour and the total fixed utility cost. Show the equation for determining total utility costs. If Joey plans on using 1500 machine hours, what will the total utility bill be using the equation in part 2.