The relationship between the "pairs of jeans" (x) and the "total cost" (y) are proportional, you can express this relationship as follows:
[tex]y=kx[/tex]
Where "k" is the constant of proportionality, to calculate the value of said constant, you have to divide y by x:
[tex]k=\frac{y}{x}[/tex]
For each store, you have to select one ordered pair, any will do since the constant of proportionality is a constant value.
Jenny's Jean Store:
In the graph, the "pairs of jeans" are on the x-axis, and "the total cost" is on the y-axis.
Choose one ordered pair from the graph, for example, (2,40), and calculate the constant of proportionality.
[tex]k=\frac{\cos t}{\text{pairs}}=\frac{\$40}{2}=\$20[/tex]
The cost per pair is $20.
Jean Warehouse:
Select any ordered pair from the graph and calculate the constant of proportionality.
For example, you can use (3,54)
[tex]k=\frac{\cos t}{\text{pairs}}=\frac{\$54}{3}=\$18[/tex]
The cost per pair is $18
So, Jenny's Jean Store charges a higher rate.
