Answer:
![y=11,600x+6,000](https://img.qammunity.org/2020/formulas/mathematics/college/psbtt8jluyejjmj11gwh9yz41389434v7n.png)
Yearly sales in 1990: $98,800.
Explanation:
We have been given that the sales of a certain appliance dealer can be approximated by a straight line. Sales were $6000 in 1982 and $ 64,000 in 1987.
If at 1982,
then at 1987 x will be 5.
Now, we have two points (0,6000) and (5,64000).
![\text{Slope}=(64,000-6,000)/(5-0)](https://img.qammunity.org/2020/formulas/mathematics/college/8bahlnzd77tdng218ne86y07hclf2hovib.png)
![\text{Slope}=(58,000)/(5)](https://img.qammunity.org/2020/formulas/mathematics/college/dyjnznyrs9uwb3o1srues8usqu10nu3wkx.png)
![\text{Slope}=11,600](https://img.qammunity.org/2020/formulas/mathematics/college/c4mje3at8qeew9ckhk5wl79gnsr758xhwa.png)
Now, we will represent this information in slope-intercept form of equation.
, where,
m = Slope,
b = Initial value or y-intercept.
We have been given that at
, the value of y is 6,000, so it will be y-intercept.
Substitute values:
![y=11,600x+6,000](https://img.qammunity.org/2020/formulas/mathematics/college/psbtt8jluyejjmj11gwh9yz41389434v7n.png)
Therefore, the equation
represents yearly sales.
Now, we will find difference between 1990 and 1982.
![1990-1982=8](https://img.qammunity.org/2020/formulas/mathematics/college/fpkky8n9enqbihd4sfq9o3ipibu492qs1c.png)
To find yearly sales in 1990, we will substitute
in the equation.
![S=11,600(8)+6,000](https://img.qammunity.org/2020/formulas/mathematics/college/zl19tfssjw3l0v8rhfk86cuz1inxqw6y3z.png)
![S=92,800+6,000](https://img.qammunity.org/2020/formulas/mathematics/college/xm51nk73kvu6e2puajew95tyry1afixkra.png)
![S=98,800](https://img.qammunity.org/2020/formulas/mathematics/college/9g8ompmbykc2byjaz8u0f74g6ur7y5qkbz.png)
Therefore, the yearly sales in 1990 would be $98,800.