The answer is the top option.
+2.15.
Explanation: subtract 6.3 by 4.15 = 2.15 so you add 2.15
The formula for the growth rate is given by
![y=a(b)^x](https://tex.z-dn.net/?f=%20y%3Da%28b%29%5Ex%20)
Now when b is greater than 1 , then it is increasing function
and when b is less than 1 , then it is decreasing function.
Now in the function
![22000(.88)^{(x+2)}](https://tex.z-dn.net/?f=%2022000%28.88%29%5E%7B%28x%2B2%29%7D%20)
here value of b is 0.88 , which is less than 1 , so it is decreasing function
And decay rate is given by
1-r = 0.88
Subtract 1 from both sides
-r = 0.88-1
-r = -0.12
r = 0.12
or r= 12%
It means it is decreasing at a rate of 12%
Hence Option C is correct
C.The price of the boat decreases by 12% every year.