For this case we have the following function:
f (x) = (1/3) * (4 ^ x)
We must evaluate the function for x = 2
We have then:
f (2) = (1/3) * (4 ^ 2)
Rewriting:
f (2) = (1/3) * (16)
f (2) = 16/3
Answer:
The function evaluated at x = 2 is:
f (2) = 16/3
option A
Answer:
35% off
Step-by-step explanation:
John's effective annual rate is about
(1 +.0576/4)^4 -1 ≈ 5.8856%
According to the "rule of 72", John's money will have doubled in
72/5.8856 = 12.23 years
John's balance will be $4500 in 1989.
_____
Since you're only concerned with the year (not the month), you don't actually need to determine the effective annual rate. The given rate of 5.76% will tell you 72/5.76 = 12.5 years. The actual doubling time is closer to 12.12 years, so using the effective rate gives results that are closer, but "good enough" is good enough in this case.
