$10.$ Compute the monthly cost of gas In cell C$21,$ enter a formula to calculate the number of miles you expect to drive each month the value of number of miles $($cell from the Data sheet$)$ by the average MPG for the multiplied by the price of a gallon of gas $($cell from the Data sheet$)$ Copy the formula to the appropriate cells for the other vehicles D$21$:F$21$ display an error or a value of display formulas and check for errors you still can't find the error, try displaying the precedent arrows The references to the cells on the Data sheet should use absolute referencesIf they do not, the formula will update incorrectly when you copy it across the row