Lesson 2: Identifying Proportional Relationships — Practice Questions

1. 1. Which of the following best describes the graph of a proportional relationship?

   • A. A straight line passing through the origin (0, 0).
   • B. Any straight line, regardless of where it starts.
   • C. A curved line that passes through the origin (0, 0).
   • D. A line that does not have to be straight.

2. 2. A recipe for a fruit smoothie is proportional. It calls for 6 ounces of yogurt for every 2 bananas. If you use 3 bananas, how many ounces of yogurt do you need? ___

3. 3. A taxi fare includes a 3 dollar flat fee plus 2 dollars per mile. Is the relationship between the total cost and the miles driven proportional?

   • A. No, because the graph does not pass through the origin.
   • B. Yes, because the cost per mile is constant.
   • C. No, because the cost increases with distance.
   • D. Yes, because the graph is a straight line.

4. 4. The table shows a proportional relationship between the number of books ($x$) and the total weight in pounds ($y$). Find the missing value. | x | y | |---|---| | 3 | 12 | | 5 | 20 | | 7 | $\_\_\_$ |

5. 5. A recipe calls for 3 cups of sugar for every 6 cups of flour. If the relationship between sugar ($y$) and flour ($x$) is proportional, what is the constant of proportionality, $k$? ___

6. 6. The quantities $x$ and $y$ are in a proportional relationship. If $y = 20$ when $x = 4$, what is the value of $y$ when $x = 9$? ___

7. 7. Which equation below represents a proportional relationship between $x$ and $y$?

   • A. $y = x + 5$
   • B. $y = 7x$
   • C. $y = x^2$
   • D. $y = \frac{12}{x}$

8. 8. The cost of renting a scooter is proportional to the number of hours rented. If it costs 45 dollars for 3 hours, how many dollars would it cost to rent for 5 hours? ___

9. 9. In any proportional relationship, what must be the value of the dependent variable $y$ when the independent variable $x$ is zero?

   • A. 1
   • B. 0
   • C. It depends on the constant of proportionality.
   • D. It cannot be determined.