Solution:
The decreasing function is given as:
[tex]y = a(1-r)^t[/tex]
Where,
y is future value
a is initial value
r is decreasing rate
t is number of years
From given,
a = 4800
t = 5
[tex]r = 8.25 \% = \frac{8.25}{100} = 0.0825[/tex]
Therefore,
[tex]y = 4800(1 - 0.0825)^5\\\\y = 4800 \times 0.9175^5\\\\y = 4800 \times 0.6501\\\\y = 3120.841[/tex]
Thus the area after 5 years is 3120.841 square kilometer
