It would be 17.862 gallons. Assuming that each gas station offers the same price for gas, you can divide each total by 2.75 (the cost) giving you the gallons for each one (round to the nearest Thousandth Ex. 7.3337--->7.334), you can then add them together to get the total
G=the total gallons of gas bought Equation: (12.073/2.75)+(12.695/2.75)+(11.913/2.75)+(12.442/2.75)=G (4.390)+(4.616)+(4.332)+(4.524)=G 17.862 gallons=G