growth and decay?

Question

The price of a gallon of gas in 2009 was $1.78 and it has increased 31% per year.

 

a. Find an equation to model the gas price since 2009.

 

b. According to your model, what is the average cost of a gallon of gas currently?

 

c. If the increase continues, when will a gallon of gas cost $8.50? (Solve graphically.)

Answer 1

THIS IS NOT AN ACCURATE FACT because the gasoline prices fluctuate a lot.

 

Taking this claim at face value, the formula would be P(t) = (1.78)1.31^t   t years after 2009.