1. 2.2 Constant Rates of Change
How can you identify and represent proportional relationships?

2. ADDITIONAL EXAMPLE 1
Randall earns money fixing computers. Is the relationship between the amount Randall earns and the number of days a proportional relationship?
Yes; the constant rate of change is $175 per day.

3. ADDITIONAL EXAMPLE 2
Two pounds of peaches cost $4.50, 5 pounds cost $11.25, and 10 pounds cost $ Show that the relationship between the number of pounds of peaches and the cost is a proportional relationship. Then write an equation for the relationship.

4. 2.2 LESSON QUIZ
7.4.A
Craig earns extra money as a lifeguard. He earns $37 for 4 hours and $64.75 for 7 hours. 1.
Explain how you know whether the relationship between earnings and time is a proportional relationship.
Both rates have the same unit rate, $9.25 per hour.

5. Craig earns extra money as a lifeguard
Craig earns extra money as a lifeguard. He earns $37 for 4 hours and $64.75 for 7 hours. 2.
Identify the constant of proportionality, and write an equation for the proportional relationship.
9.25; If y = earnings and x = hours, = 9.25. 3.
Write an equation for the following proportional relationship.
= 7.5.

6. How can you identify and represent proportional relationships?
A proportional relationship will have a rate of change that is constant between any two quantities. Find the constant of proportionality, k, and use it to express the relationship as an
equation in the form = k.