Answer:
The graph in the attached figure
Explanation:
we have
![f(x)=18(0.8^(x))](https://img.qammunity.org/2020/formulas/mathematics/high-school/6qz9nepr6i2qq3xmxpjsoip7wx1wp8j3ob.png)
This is a exponential function of the form
![f(x)=a(b^(x))](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2slaif8k8lw5gb6yadst4ilvo7awjvuexm.png)
where
a is the initial value (the y-intercept of the function)
b is the base
r is the rate
b=1+r
In this problem we have
a=18
b=0.8
r=0.8-1=-0.2=-20% is a decay function
using a graphing tool
The graph in the attached figure