Exploring bivariate numerical data

Making and describing scatterplots

Learn

Constructing a scatter plot
(Opens a modal)
Example of direction in scatterplots
(Opens a modal)
Positive and negative associations in scatterplots
(Opens a modal)
Bivariate relationship linearity, strength and direction
(Opens a modal)
Describing scatterplots (form, direction, strength, outliers)
(Opens a modal)

Practice

Making appropriate scatter plotsGet 3 of 4 questions to level up!
Positive and negative linear associations from scatter plotsGet 3 of 4 questions to level up!
Describing trends in scatter plotsGet 3 of 4 questions to level up!
Describing scatterplotsGet 3 of 4 questions to level up!

Correlation coefficients

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Calculating correlation coefficient r
(Opens a modal)
Example: Correlation coefficient intuition
(Opens a modal)

Practice

Correlation coefficient intuitionGet 3 of 4 questions to level up!

Least-squares regression equations

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Introduction to residuals and least-squares regression
(Opens a modal)
Calculating residual example
(Opens a modal)
Calculating the equation of a regression line
(Opens a modal)
Interpreting slope of regression line
(Opens a modal)
Interpreting y-intercept in regression model
(Opens a modal)
Using least squares regression output
(Opens a modal)

Practice

Calculating and interpreting residualsGet 3 of 4 questions to level up!
Calculating the equation of the least-squares lineGet 3 of 4 questions to level up!
Interpreting slope and y-intercept for linear modelsGet 3 of 4 questions to level up!
Using least-squares regression outputGet 3 of 4 questions to level up!

Assessing the fit in least-squares regression

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Residual plots
(Opens a modal)
R-squared intuition
(Opens a modal)
R-squared or coefficient of determination
(Opens a modal)
Standard deviation of residuals or root mean square deviation (RMSD)
(Opens a modal)
Interpreting computer regression data
(Opens a modal)
Interpreting computer output for regression
(Opens a modal)
Impact of removing outliers on regression lines
(Opens a modal)

Practice

Residual plotsGet 3 of 4 questions to level up!
Influential pointsGet 3 of 4 questions to level up!

About this unit

We use scatter plots to explore the relationship between two quantitative variables, and we use regression to model the relationship and make predictions. This unit explores linear regression and how to assess the strength of linear models.