The price of fuel may increase due to demand and decrease due to overproduction. Marco is studying the change in the price of two types of fuel, A and B, over time.

The price f(x), in dollars, of fuel A after x months is represented by the function below:

f(x) = 2.96(1.04)x

Part A: Is the price of fuel A increasing or decreasing and by what percentage per month? Justify your answer. (5 points)

Part B: The table below shows the price g(m), in dollars, of fuel B after m months:

m (number of months) 1 2 3 4
g(m) (price in dollars) 3.04 3.22 3.41 3.61

Which type of fuel recorded a greater percentage change in price over the previous month? Justify your answer. (5 points)

1 answer

Fuel A is .04 or 4% OF THE FIRST YEAR increase each year (simple interest)
for fuel B
3.22 / 3.04 = 1.06 or 6% increase per month (3.61/3.41 is also 6% )
This is not only higher interest percent but is COMPOUNDED
3.61/3.04 = 1.188 during 3 years or total of 6.2% per year if it were simple interest