Answer:

Yearly sales in 1990: $98,800.
Step-by-step 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.
 then at 1987 x will be 5.
Now, we have two points (0,6000) and (5,64000). 



Now, we will represent this information in slope-intercept form of equation.
 , where,
, 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.
, the value of y is 6,000, so it will be y-intercept.
Substitute values:

Therefore, the equation  represents yearly sales.
 represents yearly sales.
Now, we will find difference between 1990 and 1982.

To find yearly sales in 1990, we will substitute  in the equation.
 in the equation.



Therefore, the yearly sales in 1990 would be $98,800.