Scatter Plots Test – Grade 8 Math (Printable PDF)

Question 1 Reading a scatter plot (3 points)

Eight runners trained for different numbers of days, and the graph shows how many laps each ran in 14 minutes.

1. Describe the direction and form of the association. (1 point)
2. Identify any outlier. (1 point)
3. Is the association strong or weak for the points that follow the pattern? Explain. (1 point)

Question 2 Name the association (2 points)

Describe each situation as a positive association, a negative association, or no association.

1. The age of a used car and its selling price (1 point)
2. The height of a student and the student’s favorite number (1 point)

Question 3 Plot the data (3 points)

Plant heights after different amounts of daily sun: (2, 6), (3, 9), (4, 10), (5, 13), (6, 15), (7, 16), (8, 20) with hours of sun first.

1. Plot the seven points on the grid. (2 points)
2. Describe the association. (1 point)

Question 4 Line or curve? (2 points)

Pairs (0, 2), (1, 3), (2, 6), (3, 11), (4, 18) are plotted. Is the association linear or nonlinear? Use the differences in y to explain.

Question 5 Clusters and gaps (3 points)

The scatter plot shows the age of eight students and their typing speed.

1. Describe the two clusters. (2 points)
2. Describe the overall association. (1 point)

Question 6 Strong or weak (2 points)

In scatter plot A the points lie close to a rising line. In scatter plot B the points rise in general but are spread widely around the line.

1. Which plot shows the stronger association? (1 point)
2. Explain your choice. (1 point)

Question 7 Study time data (3 points)

Hours studied and test grade for eight students: (0.5, 55), (1, 60), (1.5, 68), (2, 70), (2.5, 77), (3, 80), (3.5, 86), (4, 90), plus one student at (2, 30).

1. Describe the association shown by the main group. (1 point)
2. Name the outlier. (1 point)
3. Give a possible reason for the outlier. (1 point)

Question 8 Tree growth (2 points)

A scatter plot of the age of a tree and the width of its trunk shows points that rise quickly at first and then rise more slowly. Describe the association.