Lesson 7Observing More Patterns in Scatter Plots

Let's look for other patterns in data.

Learning Targets:

  • I can pick out clusters in data from a scatter plot.
  • I can use a scatter plot to decide if two variables have a linear association.

7.1 Notice and Wonder: Nonlinear Scatter Plot

What do you notice? What do you wonder?

 

7.2 Scatter Plot City

Your teacher will give you a set of cards. Each card shows a scatter plot.

  1. Sort the cards into categories and describe each category.

  2. Explain the reasoning behind your categories to your partner. Listen to your partner’s reasoning for their categories.

  3. Sort the cards into two categories: positive associations and negative associations. Compare your sorting with your partner’s and discuss any disagreements.

  4. Sort the cards into two categories: linear associations and non-linear associations. Compare your sorting with your partner’s and discuss any disagreements.

7.3 Clustering

How are these scatter plots alike? How are they different?

4 scatter plots labeled A, B, C, and D.

Lesson 7 Summary

Sometimes a scatter plot shows an association that is not linear:

a scatter plot with points in the shape of a parabola

We call such an association a non-linear association. In later grades, you will study functions that can be models for non-linear associations.

Sometimes in a scatter plot we can see separate groups of points.

a scatter plot and a copy of the same scatter plot with two sets of data being circled

We call these groups clusters

Lesson 7 Practice Problems

  1. Literacy rate and population for the 12 countries with more than 100 million people are shown in the scatter plot. Circle any clusters in the data.

    a scatter plot showing population and literacy rates
  2. Here is a scatter plot:

    a scatter plot showing a strong positive correlation between the age in weeks and the weight in pounds

    Select all the following that describe the association in the scatter plot:

    1. Linear association
    2. Non-linear association
    3. Positive association
    4. Negative association
    5. No association
  3. For the same data, two different models are graphed. Which model more closely matches the data? Explain your reasoning.

    a scatter plot with a positive slope
    a scatter plot with a positive slope
  4. Here is a scatter plot of data for some of the tallest mountains on Earth.

    The heights in meters and year of first recorded ascent is shown. Mount Everest is the tallest mountain in this set of data.

    1. Estimate the height of Mount Everest.
    2. Estimate the year of the first recorded ascent of Mount Everest.
    a scatter plot showing the year of first ascent and height in meters
  5. A cone has a volume V , radius r , and a height of 12 cm.

    1. A cone has the same height and \frac13 of the radius of the original cone. Write an expression for its volume.
    2. A cone has the same height and 3 times the radius of the original cone. Write an expression for its volume.