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Scatter Plots and Correlations. Lesson 3.6. What is a scatter plot?. Ice cream sales. Types of Correlation. Positive correlation. Negative correlation. Strength of Correlation. STRONG. WEAK. NONE. 5 Categories of Correlation. Weak positive. Strong positive. None. Strong negative.
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Scatter Plots and Correlations Lesson 3.6
What is a scatter plot? Ice cream sales
Types of Correlation Positive correlation Negative correlation
Strength of Correlation STRONG WEAK NONE
5 Categories of Correlation Weak positive Strong positive None Strong negative Weak negative
Correlation Coefficient CC= 1 CC= 0.5 CC= 0.8 CC= 0 CC= -0.5 CC= -1 CC= -0.8
Intermission • Silently record key take-aways and HOT questions
Intermission • With partner: clarify misunderstandings or capture missing information • Your notes should be able to answer: • What is a scatter plot? • What are the two types of correlation? • What are the three ways to describe the strength of correlation? • What are the 5 categories of correlations? • What is a correlation coefficient (CC)? • What does the plot look like for various CC’s?
College Lecture Part II
Creating Scatter Plots Step 1: Identify Variables • Would it make more sense that the population below the poverty line depended on the life expectancy, or that the life expectancy depends on the population below the poverty line? • Independent variable: population below poverty level • Dependent variable: life expectancy
Creating Scatter Plots Step 2: Label axes Step 3: Plot points Step 4: Estimate line of best fit Population Below Poverty Line v. Life Expectancy, by Country Life expectancy (years) Population below poverty level (%)
Check for Understanding • With partners answer question #1 below: d. STRETCH: Sketch a graph that would correspond to a correlation coefficient 0.2.
Check for Understanding • Silently check that your notes can answer: • What are the 4 steps to creating a scatter plot? • How do you determine which quadrant to use? • How do you know where to start labeling each axis? • What does a break in the axis mean? • How do you estimate the line of best fit? • Do you have the example scatter plot correctly completed?