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Unit 6

The Slope of a Fitted Line & Observing More Patterns in Scatter Plots

Associations in Data

Lesson 6/7

8.SP.A.1: Construct and interpret scatter plots for bivariate measurement data to investigate patterns of association between two quantities. Describe patterns such as clustering, outliers, positive or negative association, linear association, and nonlinear association.

8.SP.A.2: Know that straight lines are widely used to model relationships between two quantitative variables. For scatter plots that suggest a linear association, informally fit a straight line, and informally assess the model fit by judging the closeness of the data points to the line.

8.SP.A.3: Use the equation of a linear model to solve problems in the context of bivariate measurement data, interpreting the slope and intercept.

Expressions and Equations

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Estimating Slope

Unit 6 ● Lesson 6/7

1 min individual - 1 min team share - 3 mins class share

Page 289

Coach9’s super cool method to find slope between 2 points:

But, which 2 points?

(-4, -6), (5, 2)

+4,+6

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Add the opposite >>>

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Estimating Slope

Unit 6 ● Lesson 6/7

1 min individual - 1 min team share - 3 mins class share

Page 289

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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  • Let's look at how changing one variable changes another & Let's look for other patterns in data.

Unit 6 ● Lesson 6/7

We will be able to use a scatter plot to decide if two variables have a linear association so that we can use the slope of a line fit to data in a scatter plot to say how the variables are connected

Learning

Goal

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Where were we? Where are we? Where are we going?

Unit 6 ● Lesson 6/7

Agenda Review

You are successful today when...,

  • You can use the slope of a line fit to data in a scatter plot to say how the variables are connected in real-world situations.
  • You can pick out clusters in data from a scatter plot.
  • You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.2 Activity: Describing Linear Associations

You can use a scatter plot to decide if two variables have a linear association.

As __________ increases, __________ tends to __________

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.2 Activity: Describing Linear Associations

You can use a scatter plot to decide if two variables have a linear association.

5 mins total

2 mins individual - 1 minutes group - 2 min class share

pg 289-90

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.2 Activity: Describing Linear Associations

You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.2 Activity: Describing Linear Associations

You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.2 Activity: Describing Linear Associations

You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.3 Activity: Interpreting Slopes

You can use a scatter plot to decide if two variables have a linear association.

5 mins total

2 minutes group - 3 min class share

pg 291

Only price to carat (weight.)

Slope ≅ 5,521

y-intercept

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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6.4 Activity: Positive or Negative?

You can use a scatter plot to decide if two variables have a linear association.

5 mins total

Q1 only: 2 minutes group - 3 min class share

pg 293

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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7.3 Activity: Clustering

You can use a scatter plot to decide if two variables have a linear association.

10 mins total

4 minutes group - 4 min class share

pg 300

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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7.3 Activity: Clustering

You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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7.3 Activity: Clustering

You can use a scatter plot to decide if two variables have a linear association.

  • Clustering of the data can reveal hidden patterns.
  • Usually, clustering means there are subgroups within our data that may represent different trends.
  • For example, the lower half of the data may represent females and the upper half may represent males, so we can see that there are different patterns within the different subgroups.

When clustering is present, it may be helpful to investigate the cause of the separation and analyze the data within the subgroups rather than as a whole.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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7.2 Activity: Scatter Plot City

You can use a scatter plot to decide if two variables have a linear association.

10 mins total

6 minutes group - 4 min class share

pg 299

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Glossary

You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Glossary

You can use a scatter plot to decide if two variables have a linear association.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Lesson Synthesis

You can use a scatter plot to decide if two variables have a linear association.

The points in a scatter plot do not lie along a straight line.

There is not a constant increase or decrease of one variable based on the other.

The points in a scatter plot are clumped together in different groups.

There may be multiple patterns present within the data. Perhaps there are subgroups that show different patterns.

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Lesson Synthesis

Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Make Your Own Scatter Plot

You can use a scatter plot to decide if two variables have a linear association.

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Cool-down

Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Unit 6 ● Lesson 6/7

  • I can use the slope of a line fit to data in a scatter plot to say how the variables are connected in real-world situations.
  • 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.

Learning

Targets

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Glossary

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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Glossary

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Slides are CC BY NC Kendall Hunt Publishing. Curriculum excerpts are CC BY Open Up Resources, with adaptations CC BY Illustrative Mathematics.

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This slide deck is copyright 2020 by Kendall Hunt Publishing, https://im.kendallhunt.com/, and is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0), https://creativecommons.org/licenses/by-nc/4.0/.

All curriculum excerpts are under the following licenses:

IM 6–8 Math was originally developed by Open Up Resources and authored by Illustrative Mathematics, and is copyright 2017-2019 by Open Up Resources. It is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). OUR's 6–8 Math Curriculum is available at https://openupresources.org/math-curriculum/.

Adaptations and updates to IM 6–8 Math are copyright 2019 by Illustrative Mathematics, and are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).

Adaptations to add additional English language learner supports are copyright 2019 by Open Up Resources, and are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).

The Illustrative Mathematics name and logo are not subject to the Creative Commons license and may not be used without the prior and express written consent of Illustrative Mathematics.

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