Given:
The exponential function is:
![y=630(0.94)^x](https://img.qammunity.org/2022/formulas/mathematics/college/in12enl46ux6b4q29ie50d0ddwv6x3986k.png)
To find:
The percentage rate of increase or decrease.
Solution:
The general exponential function is:
...(i)
Where, a is the initial value, |r| is the growth rate in decimals if r>0 and |r| is the decay rate in decimal if r<0.
The exponential function is:
![y=630(0.94)^x](https://img.qammunity.org/2022/formulas/mathematics/college/in12enl46ux6b4q29ie50d0ddwv6x3986k.png)
It can be written as:
![y=630(1-0.06)^x](https://img.qammunity.org/2022/formulas/mathematics/college/zbjgy9fm3xdh6u4cogyimenw75dd11dql4.png)
...(ii)
On comparing (i) and (ii), we get
![r=-0.06](https://img.qammunity.org/2022/formulas/mathematics/college/lo68jyp7wccuy3h3vihh3ahu4n6gw9m42w.png)
Since r is negative, therefore the given function is a decreasing or decay function.
Now,
So, the rate of decrease is 0.06. Multiply this number by 100 to get the percentage.
![0.06* 100=6\%](https://img.qammunity.org/2022/formulas/mathematics/college/4npwelxw2khb7gglnd63p60t6my3azbt84.png)
Therefore, the rate of decrease is 6%.