In the graph is represented Adrienne's profit/month (y-axis) based on the number of haircuts she made (x-axis)
a. To determine her profit when she does 21 haircuts, you have to identify the number in the x-axis, go up until you reach the lines, and then left following the horizontal line to see the corresponding value of y (profit)
When she makes 21 haircuts, the makes a profit of $150
b.
To determine the line you need to use the following formula
[tex]m=\frac{y_1-y_2}{x_1-x_2}[/tex]
Where
m is the slope
(x₁,y₁) are the coordinates of one point of the line
(x₂,y₂) are the coordinates of a second point of the line
You have to use two points of the line, for example, (12,0) and (15,50), replace them in the formula:
[tex]\begin{gathered} m=\frac{50-0}{15-12} \\ m=\frac{50}{3} \\ m\cong16.67 \end{gathered}[/tex]
The slope of the line is $16.67/haircut
c.
The slope represents the variation in y for every unit increase of x.
In the context of the story, the slope indicates that Adrienne's profit increases by $16.67 for every increase of one haircut she performs.
