Answer:
Option A
f(x) = 12.5(1.6)^x
Step-by-step explanation:
The number of gnats the scientists have gathered
At 0 hours, they gathered 12 gnats.
Checking all the options, applying x = 0 makes the index part become 1 (Anything raised to the power zero is 1).
So, we have the following functions
f(x) = 12.5
f(x) = 12.6
f(x) = 6.2
f(x) = 1.6
This has reduced our work, as we can screen out options C and D, they are too far from 12. This leaves us with option A and B.
At 1 hour, they gathered 20 gnats.
Checking options A and B
A. f(x) = 12.5(1.6)
= 20
B. f(x) = 12.6(6.2)
By inspection, 12 × 6 is already 72,
12.6 × 6.2 will be more.
By these, we can conclude that f(x) = 12.5(1.6)^x has the best models the number of gnats the scientists have gathered after the number of hours listed in the given table.
