The number of miles a car can be driven is proportional to the number of gallons of gasoline that uses the car can be driven 14 mi. per half gallon of gasoline used what is the constant of...

The number of miles a car can be driven is proportional to the number of gallons of gasoline that uses the car can be driven 14 mi. per half gallon of gasoline used what is the constant of proportionality for the relationship between miles driven in gallons of gasoline