Respuesta :

We have a proportional relationship like:

[tex]y=k\cdot x[/tex]

where k is the constant of proportionality or the unit rate, depending on the context.

If we have a graph, the value of k is the value of the slope.

Knowing one pair (x,y) we can calculate the unit rate k as:

[tex]k=\frac{y}{x}[/tex]

In this case, we have one known point that is (6, 2.58), that means that 6 pounds of nails cost $2.58.

We can calculate the unit rate as:

[tex]k=\frac{2.58\$}{6\text{ pounds of nails}}=0.43\$\text{ per pound of nails}[/tex]

Answer: the unit rate is $0.43 per pound of nails.