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PlayOwl

Mathematics · Grade 8

Scatter Plots and Two-Variable Data

Learners plot paired data and describe the pattern in a scatter plot: direction, linear or nonlinear form, clusters and outliers, without confusing association with cause. They fit straight lines informally and judge them by how close the points are, use a line's equation to predict and to interpret slope and intercept in context, and finish with two-way tables, using relative frequencies to decide whether two categorical variables seem associated.

  • 4 lessons
  • About 95 minutes
  • Scatter plots and two-variable data check: 10 questions
  • Ways to answer: choose an answer, type a fraction, draw a graph, plot points, match pairs and type a number
See plans Included with Family, Teacher and School plans. Open in PlayOwl

What learners will discover

  • Construct and interpret scatter plots of paired data, describing positive, negative or no association, linear or nonlinear form, clusters and outliers.
  • Informally fit a straight line to data that show a linear association, and judge the fit by how close the points are to the line.
  • Use the equation of a linear model to make predictions, and interpret its slope and intercept in context.
  • Construct and interpret two-way tables, using relative frequencies to describe a possible association between two categorical variables.

Lessons

  1. Scatter plots and association 7 steps4 practiceabout 23 min
  2. Fitting a line by eye 8 steps5 practiceabout 24 min
  3. Using a linear model 7 steps4 practiceabout 23 min
  4. Two-way tables and relative frequency 8 steps5 practiceabout 25 min
  5. Scatter plots and two-variable data check 10 questions at the end

Keep exploring

Games to practice with

  • Number-Line HopHelp the frog hop to the right number — from counting to negative fractions.
  • Algebra BalanceKeep the scale level and the equation true, step by step.
  • Function FactoryFeed the machine, crack its rule and predict what comes out.

More 8th grade math

Guide for grown-ups