Question

Mark wants to ship a package to his parents for Christmas. He looked at the following graph, which shows a proportional relationship between the cost of shipping ($) and the weight (lbs) of the package.

If Mark's package weighs 25 pounds, how much will it cost him to ship the package?

Answer 1

12.50

Step-by-step explanation:

Answer 2

$12.5

Step-by-step explanation:

The graph showing the relationship is attached.

To solve the problem, we have to first get the equation of the graph. From the graph, the points (60, 30) and (20, 10) lie on the graph. The equation of a line passing through two points is:

`y-y_1=(y_2-y_1)/(x_2-x_1)(x-x_1)\\ \\y-30=(10-30)/(20-60)(x-60)\\\\ y-30=(-20)/(-40)(x-60)\\ \\y-30=(1)/(2) (x-60)\\\\y=(1)/(2) x-30+30\\\\y=(1)/(2) x \\\\Therefore\ when \ the\ package\ weighs\ 25\ pound(x=25)\\\\y=(1)/(2)(25)\\ \\y=12.5\\\\y=\$12.5`