Compare rates of change. The equation below can be used to find the length of a foot or forearm when you know one or the other.

length of foot = 0.860 • length of forearm + 3.302

Let y = length of foot and x = length of forearm. This equation can be simplified to:

y = 0.860x + 3.302

Compare rates of change.

The equation below can be used to find the length of a foot or forearm when you know one or the other.

length of foot = 0.860 • length of forearm + 3.302

Let y = length of foot and x = length of forearm. This equation can be simplified to:

y = 0.860x + 3.302

Using this equation, how long would the foot of a person be if his forearm was 25 inches long?
Using this equation, how long would the foot of a person be if his forearm was 25 inches long?

What is the rate of change of the blue equation?

Compare the blue equation to yours:

Are they the same?

Which has a greater rate of change?

Why do you think the values are different?

Is the relation in your data a function?
Why or why not?
Could the blue equation represent a function? Why or why not? Explain your answer.