We have a situation where the demand of a computer depends on the price.
We know that quantity sold and price have a linear relationship.
We also know that:
- When priced at $1000 (p = 1000), he sold 80 (q = 80).
- When priced at $750 (p = 750), he sold all the stock (q = 100).
We then have two points for the function: (1000, 80) and (750, 100).
With two points we can define a linear function.
We can calculate the slope of the line as:
![m=(q_2-q_1)/(p_2-p_1)=(100-80)/(750-1000)=(20)/(-250)=-0.08](https://img.qammunity.org/2023/formulas/mathematics/college/c7dr1o9v81j9cathysi9hswait142enzo9.png)
Then, we can write the linear function in point-slope form:
![y-80=-0.08(x-1000)](https://img.qammunity.org/2023/formulas/mathematics/college/fdhfl031kjpqrymdee3uoqq64fy8l3v6vp.png)
Now, we can calculate the quantity q for p = 1425:
![\begin{gathered} y-80=-0.08(1425-1000) \\ y=-0.08\cdot425+80 \\ y=-34+80 \\ y=46 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/wrscqw52jvti1qgdlkwyu8uqx1cnipw2yh.png)
Answer:
The linear model is y = -0.08(x-1000) + 80.
For a price of $1425, it is expected that 46 units are sold.