what am I doing wrong here

please help me in excel

1. Automobiles have different fuel economies ( mpg ), and commuters drive different distances to work or school. Suppose that a state Department of Transportation (DOT) is interested in measuring the average monthly fuel consumption of commuters in a certain city. The DOT might sample a group of commuters and collect information on the number of miles driven per day, number of driving days per month, and the fuel economy of their cars. (10 Points) a. Develop a predictive model for calculating the amount of gasoline consumed, using the following symbols for the data. G= gallons of fuel consumed per month m= miles driven per day to and from work or school d= number of driving days per month f= fuel economy in miles per gallon b. Suppose that a commuter drives 30 miles round trip to work 20 days each month and achieves a fuel economy of 34mpg. How many gallons of gasoline are used? c. Develop a spreadsheet model for gasoline usage, apply the principles of spreadsheet modelling