8th Grade Scatter Plots Quizzes

Scatter plots are a major topic in the 8th-grade Common Core State Standards for Statistics and Probability. Students learn to construct and interpret scatter plots for bivariate data, describe patterns like clustering and outliers, and informally fit a straight line (a line of best fit) to model linear associations.

Introduce the line of best fit as a 'summary' of the data's trend. A good hands-on method is to give students a clear plastic ruler or a piece of uncooked spaghetti. Ask them to place it on their scatter plot to find a line that passes through the 'middle' of the points, with roughly an equal number of points above and below it.

A frequent error is forcing the line to go through the origin, even when it's not appropriate for the data. Another is simply connecting the first and last data points, ignoring the overall trend. Students may also draw a line that is too steep or too flat because they are overly influenced by outliers.

The most effective practice involves the full cycle of data analysis. Quizzes should provide real-world data sets and ask students to create the scatter plot, describe the association, draw a line of best fit, and use the line to make predictions for values not in the original data set.

These quizzes are versatile for any 8th-grade classroom. Print the PDF for students to practice drawing plots and lines of best fit by hand. You can then use the Wayground for Teachers app to quickly scan and grade their paper submissions using the provided answer key. Alternatively, assign the quiz as a digital quiz on Wayground for immediate feedback.

For students who find plotting points tedious, provide quizzes where the plot is already created and the focus is on interpretation. When using Wayground's digital format, you can enable Read Aloud for students who struggle with reading. For a challenge, give advanced students data sets with non-linear patterns and ask them to describe the relationship.