Answer:
Rate of change = $0.55/pound
Step-by-step 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
such that
co-ordinate represents the mass of the item in pounds and
co-ordinate represents the cost of the item in dollars.
So, we will have two points
![(2,6.09)\ and\ (7,8.84)](https://tex.z-dn.net/?f=%282%2C6.09%29%5C%20and%5C%20%287%2C8.84%29)
Rate of change is the slope
of the line joining the points and is given by:
![m=\frac{y_2-y_1}{x_2-x_1}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7By_2-y_1%7D%7Bx_2-x_1%7D)
![m=\frac{8.84-6.09}{7-2}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B8.84-6.09%7D%7B7-2%7D)
![m=\frac{2.75}{5}](https://tex.z-dn.net/?f=m%3D%5Cfrac%7B2.75%7D%7B5%7D)
![m=0.55](https://tex.z-dn.net/?f=m%3D0.55)
∴ Rate of change = $0.55/pound