In September $1984,$ when the CPI index was $100,$ a gallon of gas was $$1\mathrm{.}28.$

If the prices of a gallon of gas had increased at the rate of inflation, what would the cost of a gallon of gas in September $2022(38$ years later$)$ when the CPI index is at $296\mathrm{.}81?$

Selected Answer:

$$3\mathrm{.}62$ per gallon

Answers:

$$3\mathrm{.}62$ per gallon

$$3\mathrm{.}73$ per gallon

$$3\mathrm{.}80$ per gallon

$$4\mathrm{.}28$ per gallon