The price of a gallon of gasoline was $0.35 in 1972 when the CPI equaled 0.418. The price of a gallon of gasoline was $2.25 in 2005 when the CPI equaled 1.68. The real price of a gallon of gasoline between 1972 and 2005:

increased

Explanation:

Data provided in the question:

Price of a gallon of gasoline in 1972 = $0.35

CPI in 1972 = 0.418

Price of a gallon of gasoline in 2005 = $2.25

CPI in 2005 = 1.68

Now,

Real cost in 1972 = [ Nominal cost in 1972 ] : [ CPI in 1972 ]

= $0.35 : 0.418

= $0.837

Real cost in 2005 = [ Nominal cost in 2005 ] : [ CPI in 2005 ]

= $2.25 : 1.68

= $1.34

Hence,

The price of gallon of gasoline increased between 1972 and 2005