Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

Session 7, Part A:
Scatter Plots

In This Part: A Bivariate Data Question | Building a Scatter Plot | A Further Question

With bivariate data, there are four possible categories of data pairs. Accordingly, each person in the table can be placed into one of four categories:

 a. People with above-average arm spans and heights are in orange. b. People with below-average arm spans and above-average heights are in blue. c. People with below-average arm spans and heights are in purple. d. People with above-average arm spans and below-average heights are in green.

Arm Span

Height

 156 162 157 160 159 162 160 155 161 160 161 162 162 170 165 166 170 170 170 167 173 185 173 176

Arm Span

Height

 177 173 177 176 178 178 184 180 188 188 188 187 188 182 188 181 188 192 194 193 196 184 200 186

We can represent these categories similarly on the scatter plot:

 a. Points for people with above-average arm spans and heights are in orange. b. Points for people with below-average arm spans and above-average heights are in blue. c. Points for people with below-average arm spans and heights are in purple. d. Points for people with above-average arm spans and below-average heights are in green.

Adding both the vertical line at the mean arm span (175.5 cm) and the horizontal line at the mean height (174.8) separates the points in the scatter plot into four groups, known as quadrants:

Problem A9

Use this scatter plot to answer the following:

 a. Describe the heights and arm spans of people in Quadrant I. b. Describe the heights and arm spans of people in Quadrant II. c. Describe the heights and arm spans of people in Quadrant III. d. Describe the heights and arm spans of people in Quadrant IV.

Problem A10

 a. Based on the scatter plot, do most people with above-average arm spans also have above-average heights? b. Based on the scatter plot, do most people with below-average arm spans also have below-average heights?

 Session 7: Index | Notes | Solutions | Video