Compute the monthly cost of gas.

a$.$ In cell C$21,$ enter a formula to calculate the number of miles you expect to drive each month. Divide the value of number of miles $($cell A$5$ from the Data sheet$)$ by the average MPG for the vehicle multiplied by the price of a gallon of gas $($cell $A6$ from the Data sheet$).$

b$.$ Copy the formula to the appropriate cells for the other vehicles.

c$.$ If cells D$21$:F$21$ display an error or a value of $0,$ display formulas and check for errors.

d$.$ If you still can't find the error, try displaying the precedent arrows.

e$.$ Hint: The references to the cells on the Data sheet should use absolute references. If they do not, the formula will update incorrectly when you copy it across the row.