Question

To ship a 2-pound item it costs $6.09. To ship a 7 pound item it costs $8.84. Find the rate of change.

Answer 1

Rate of change = $0.55/pound

Explanation:

Given:

To ship a 2 pound item it costs $6.09.

To ship a 7 pound item it costs $8.84.

So, we can put the data in co-ordinates
`(x,y)` such that
`x` co-ordinate represents the mass of the item in pounds and
`y` co-ordinate represents the cost of the item in dollars.

So, we will have two points

`(2,6.09)\ and\ (7,8.84)`

Rate of change is the slope
`(m)` of the line joining the points and is given by:

`m=(y_2-y_1)/(x_2-x_1)`

`m=(8.84-6.09)/(7-2)`

`m=(2.75)/(5)`

`m=0.55`

∴ Rate of change = $0.55/pound