# Correlation/Regression

• ### The r Song

Lyrics © Mary McLellan
may sing to the tune of "Play That Funky Music" by Wild Cherry

Correlation coefficient
Represented by the R!
Correlation coefficient
The variable that you use to
represent it is the r

Repeat

• ### Standard Deviations of Residuals

Lyrics © Mary McLellan
may sing to the tune of "Billie Jean" by Michael Jackson

Standard Deviation
Standard Deviation
Of residuals

Average amount that the actual Y
(the actual Y value point- ooooh)
Varies from what’s predicted to
Become
Varies from the predicted Y

Repeat

• ### R Doesn't Change

Lyrics © Mary McLellan
may sing to the tune of "Hit Me With Your Best Shot" by Pat Benatar

You can add, subtract, multiply, divide…
Well you can even switch the x and y
Akk but negative transformations fly...
And the r doesn’t change

You can add, subtract, multiply, divide…
Well you can even switch the x and y
Akk but negative transformations fly...
And the r doesn’t change

• ### Mean Mean on the Line

Lyrics © Mary McLellan
may sing to the tune of Taylor Swift's "Shake it Off"

X-bar is the mean of X
Y-bar is the mean of Y
And the (mean, mean) point is always
On the line, on the line

Repeat

• ### Interpret the Y-Intercept

Lyrics © Mary McLellan
may sing to the tune of Miley Cyrus' "Wrecking Ball"

Interpret the Y-intercept
It happens when the X is Zero
The predicted Y is this
And it often does not make sense

Repeat

• ### Interpret the Slope

Lyrics © Mary McLellan
may sing to the tune of "The Addams Family Theme Song"

Interpret the slope (snap, snap)
Interpret the slope (snap, snap)
Interpret the slope, interpret the slope, interpret the slope

For every 1 increase in the X
The predicted Y, it does this…

Interpret the slope (snap, snap)
Interpret the slope (snap, snap)
Interpret the slope, interpret the slope, interpret the slope

Repeat

• ### Correlation Coefficient

Lyrics © Mary McLellan
may sing to the tune of "Blue Suede Shoes

There is a strong
There is a weak
Positive or negative, linear

Correlation between X and Y
Linear between X and Y

Repeat

• ### Coefficient of Determination

Lyrics © Mary McLellan
may sing to the tune of "Frosty the Snowman"

Coefficient of determination
The percent of variation that is found in the Y
Coefficient of determination
The percent of variation that is found in the Y

It can be explained by the changes in the X
or  it can be explained by the model itself, Oh

Coefficient of determination
The percent of variation that is found in the Y

Repeat