Question

Population 820 quake increases an annual rate of 22% so what will the approximate population be after 3 years?

Answer 1

The general form of exponential function ⇒⇒ $a * b^x$
Where: a is the initial value and b is the rate
b > 1 ⇒⇒ exponential growth or exponential increase
b < 1 ⇒⇒ exponential decay or exponential decrease

Given:   The initial population = 820
The annual rate = 23% = 0.23
The total ration between the adjacent years = 1+0.23 = 1.23

So, the exponential function to model this population is 
$f(x)= 820*1.23^x$

After 3 years ⇒⇒⇒ x = 3
∴ $f(x) = 820 * 1.23^3 = 1,525.91$ ≈ 1,526


The correct answer is:
$f(x)= 820*1.23^x$  ; 1,526