Lesson 8

Analyzing Bivariate Data

Lesson Narrative

In this lesson, students bring everything they have studied in the unit so far to analyze and interpret bivariate data in context (MP4). They create a scatter plot, identify outliers, fit a line, and determine and interpret the slope of the line. They compare actual and predicted values. They reflect on what they have learned about modeling bivariate data.

Learning Goals

Teacher Facing

  • Create a scatter plot and draw a line to fit bivariate data, and identify (orally and in writing) outliers that appear in the data.
  • Interpret (orally and in writing) features of a scatter plot with a line of fit, including outliers, slope of the line, and clustering.

Student Facing

Let’s analyze data like a pro.

Required Materials

Required Preparation

Class data (or data from another group if it fits the classroom culture better) from the second lesson in the unit on arm span and height.

Learning Targets

Student Facing

  • I can analyze a set of data to determine associations between two variables.

CCSS Standards

Addressing

Building Towards

Glossary Entries

  • negative association

    A negative association is a relationship between two quantities where one tends to decrease as the other increases. In a scatter plot, the data points tend to cluster around a line with negative slope.

    Different stores across the country sell a book for different prices.

    The scatter plot shows that there is a negative association between the the price of the book in dollars and the number of books sold at that price.

    Scatterplot with line of best fit.
  • outlier

    An outlier is a data value that is far from the other values in the data set.

    Here is a scatter plot that shows lengths and widths of 20 different left feet. The foot whose length is 24.5 cm and width is 7.8 cm is an outlier.

    A scatterplot with line.
  • positive association

    A positive association is a relationship between two quantities where one tends to increase as the other increases. In a scatter plot, the data points tend to cluster around a line with positive slope.

    The relationship between height and weight for 25 dogs is shown in the scatter plot. There is a positive association between dog height and dog weight.

    A scatterplot, horizontal, dog height in inches, 6 to 30 by 3, vertical, 0 to 112 by 16. Same scatterplot as previous, this time with a line through 9 comma 0 and 27 comma 80.