Answer:
Function for given situation is :
![V(t)=3000(0.70)^t](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sf22uqn3jlpacu0wq1p9bwr063lc24ih9b.png)
Value of computer after 4 years = $720.3.
Explanation:
Given that the value of a $3000 computer decreases about 30% each year. Now we need to write a function for the computers value V(t). then we need to find about how much will the computer be worth in 4 years.
It clearly says that value decreases so that means function represents decay.
For decay we use formula:
![A=P(1-r)^t](https://img.qammunity.org/2020/formulas/mathematics/middle-school/q1epjwidsz5etkhybuwu5qgmqgq5upcxrr.png)
where P=initial value = $3000,
r= rate of decrease =30% = 0.30
t= number of years
A=V(t) = future value
so the required function is
![V(t)=3000(1-0.30)^t](https://img.qammunity.org/2020/formulas/mathematics/middle-school/z1qsp171y2731suh45pt9aq2nimpuqmwbc.png)
or
![V(t)=3000(0.70)^t](https://img.qammunity.org/2020/formulas/mathematics/middle-school/sf22uqn3jlpacu0wq1p9bwr063lc24ih9b.png)
Now plug t=4 years to get the value of computer after 4 years.
![V(4)=3000(0.70)^4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/35m2scpp7x1al6339ritexje8h23txx2xx.png)
![V(4)=720.3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/89l2ly4mdq6vm0qmf9lxgcleq92qxedxr0.png)
Hence final answer is $720.3.