Have vehicles gotten more fuel-efficient over the years? Between 1960 and 1999 the size and shape of automobiles in the United S
tates has changed almost annually. The amount of fuel consumed by these vehicles has also changed. The following table describes the average fuel consumption per year per passenger car in gallons of gasoline.
The average rate of change from 1960 to 1970 is the change on the variable gallons consumed per passenger car divided by the period
average rate of change = Δg / Δt
Δg = 760 gallons - 668 gallons
Δt = 1970 year - 1960 year
760 gal - 668 gal 92 gal average rate of change = -------------------------------- = ---------- = 9.2 gal / year 1970 year - 1960 year 10 year
Answer: 9.2 gal / year
As you see for this specific period, 1960 to 1970, the vehicles increased their consumption of gas per passenge, meaning that they became less efficient.
