Lesson 11: Practice Problems

Problem 1

There is a proportional relationship between the number of months a person has had a streaming movie subscription and the total amount of money they have paid for the subscription. The cost for 6 months is $47.94. The point is shown on the graph below.

A coordinate plane with the origin labeled “O”. The horizontal axis is labeled “time in months” and the numbers 0 through 22 are indicated. The vertical axis is labeled “cost in dollars” and the numbers 0 through 180, in increments of 10, are indicated. The point with coordinates 6 comma 47.94 is indicated.

  1. What is the constant of proportionality in this relationship?

  2. What does the constant of proportionality tell us about the situation?

  3. Add at least three more points to the graph and label them with their coordinates.

  4. Write an equation that represents the relationship between , the total cost of the subscription, and , the number of months.

Problem 2

The graph shows the amounts of almonds, in grams, for different amounts of oats, in cups, in a granola mix. Label the point on the graph, find the value of , and explain its meaning.

A graph with a line starting at 0. the x axis is oats (cups) going from 1 to 5. The y axis is almonds (grams) going from 0 to 110.

Problem 3 From Unit 2 Lesson 9

To make a friendship bracelet, some long strings are lined up; then, one string is tied in a knot with each of the other strings to create a row of knots. A new string is chosen and knotted with the all the other strings to create a second row. This process is repeated until there are enough rows to make a bracelet to fit around your friend’s wrist.

Are the number of knots proportional to the number of rows? Explain your reasoning.

Problem 4 From Unit 2 Lesson 9

What information do you need to know to write an equation relating two quantities that have a proportional relationship?