Step-by-step explanation:
it is the second option
f(x) = 815.03×(1.38)^x
for year (x) 4 and 5 we need to get f(x) values in the multiple thousands.
the first and fourth options only add very little to 815.03. they can never reach the cost levels needed for the years 4 and 5.
the third option for e.g. x=4 only creates 815.03 × 2 = 1630.06, which is not 2955.65.
so, just to control, for x = 4 we get for the second option
815.03 × (1.38)⁴ = 815.03 × 3.62673936 = 2,955.901381
it is close enough to model the given data.
