Answer
[tex]f(t) = 11500 * (3)^{\frac{t}{14}}[/tex]
Explanation
Given
[tex]a = 11500[/tex] -- initial
[tex]b = 3[/tex] ---- every 14 years
Required
The exponential equation
The exponential equation is:
[tex]y =ab^T[/tex]
First, calculate the yearly rate.
Triples every 14 years, implies that:
[tex]b = 3[/tex] -- the rate
[tex]T=\frac{t}{14}[/tex] ---- time
So:
[tex]y =ab^t[/tex]
[tex]y = 11500 * (3)^{\frac{t}{14}}[/tex]
Hence:
[tex]f(t) = 11500 * (3)^{\frac{t}{14}}[/tex]