Over Lesson 6–3

Using the points in the table, graph the line. Determine whether the set of numbers in each table is proportional. Explain your reasoning.

Over Lesson 6-4

Identify Proportional Relationships

Determine whether the number of inches is proportional to the number of seconds. Explain your reasoning.

Write the rate of time to distance for each second in simplest form.

You have already used unit rates to convert measurements. (Lesson 6–3)

• Identify proportional and nonproportional relationships in tables and graphs.

• Describe a proportional relationship using an equation.

• Proportional relationships can be described using equations in the form y = kx, where k is a constant ratio..

• constant of proportionality – a constant ratio or unit rate of a proportion (k)

It costs $50 for 5 people to attend a baseball game. Write an equation comparting the cost to the number of people. How much would it cost for 10 people?

K = Cost = people

$50 = $10 = $10 person5 people 1 person

y = kx

Cost = $10 x people

Cost = $10 x 10

Cost = $100

Describe Proportional Relationships

WORK Nina charges $34.50 for 6 days of pet sitting. Write an equation relating the cost of pet sitting to the number of days. What would be the cost of pet sitting for 4 days?

Find the constant of proportionality.

K = cost = 34..50 = 34.50 ÷ 6 = 5.75 days 6

.

Describe Proportional Relationships

C = 5.75dWrite the equation.= 5.75 ● 4

Replace d with 4.

= 23Multiply.

Answer: The cost would be $23.

Howard can cut 15 lawns in 12 hours. Which is the correct equation and answer for finding how many lawns he could mow in 8 hours?

A.

B.

C.

D.