Using Graphs to Compare Relationships

Warmup

Activity #1

Complete a Table.

Diego, Lin, and Mai went from the ticket booth to the bumper cars.

• Use each description to complete the table representing that person’s journey.

(1.) Diego left the ticket booth at the same time as Tyler. Diego jogged ahead at a steady pace and reached the bumper cars in 30 seconds.

(2.) Lin left the ticket booth at the same time as Tyler. She ran at a steady pace and arrived at the bumper cars in 20 seconds.

(3.) Mai left the booth 10 seconds later than Tyler. Her steady jog enabled her to catch up with Tyler just as he arrived at the bumper cars.

Activity #2

Compare Speeds from a Graph of Proportional Relationships.

Lin and Andre biked home from school at a steady pace. Lin biked 1.5 km and it took her 5 minutes. Andre biked 2 km and it took him 8 minutes.

• Draw a graph with two lines that represent the bike rides of Lin and Andre.

• For each line, highlight the point with coordinates  (1, k)   and find k.

Who was biking faster, Lin or Andre?

Activity #3

Find the Equation of a Graph.

Here below are graphs of proportional relationships.

• Study them and choose the correct answer.

Challenge #1

Meteoroid Perseid 245 and Asteroid x travel through the solar system. Explore the applet to learn about the distance they had each traveled after a given time.

Is Asteroid x traveling faster or slower than Perseid 245? Explain how you know.

Challenge #2

The graph shows the price of different lengths of two types of rope.

If you buy $1.00 of each kind of rope, which one will be longer? Explain how you know.

Challenge #3

The graphs below show some data from a coffee shop menu. One of the graphs shows cost (in dollars) vs. drink volume (in ounces), and one of the graphs shows calories vs. drink volume (in ounces).

(1.) Which graph is which? Enter the correct titles.

(2.) Which quantities appear to be in a proportional relationship? Explain how you know.

(3.) For the proportional relationship, find the constant of proportionality. What does that number mean?

Quiz Time

https://www.ixl.com/math/grade-8/compare-proportional-relationships-represented-in-different-ways