Correlation Facts
This is the name for the measure of the strength of the relationship between 2 quantitative variables.
What is Correlation (coefficient)?
This is the explanatory variable of a study examining first year college grades associated with high school GPA.
What is high school GPA?
This is the generic way to write the least-squares regression equation.
What is y-hat = a + bx, in natural units?
Given
Predicted gas consumption(ft3)=
1344-19Temperature(Fahrenheit), this is the slope.
The range of values for correlation.
What is -1 < r < 1?
If an association in a scatterplot is linear, these are the three properties to analyze.
What are Form, Strength and Direction?
This simple formula expresses residuals.
What is e=y, actual, minus y-hat, predicted?
Since R2 = 93.25%, this is r.
What is r=0.96?
Given larger values of one variable associated with smaller values of the other, this is the sign of its slope in its LSRL.
What is a negative sign?
This is the statistical TERM for the model formed by the line of best fit.
What is The Least Squares Regression Line ?
This gives the relationship between correlation, r, and the coefficient of determination, R2 .
What is (r)2 = R2 ?
A study found children to who watch more TV tend to have lower reading scores. Hours of TV watched explained 2% of the differences in reading scores of the subjects.
This is the correlation.
What is r=-0.5?
This describes correlation given the fact that outliers can strongly alter its value.
What is sensitive to outliers?
This point is always on the least squares regression line.
What is (x-bar, y-bar)?
This is the formula for the slope of the LSRL.
What is b = r (Sy/Sx) ?
This is the residual, when actual damage was $5,000 one mile away with a model of
Predicated fire damage($thousands)=
10.28+4.92distance(miles).
What is -$10,200?
This is the PHRASE used to caution against basing a conclusion on simply an association.
What is, "Association does not equal Correlation does not equal Causation" ?
These are the values plotted on the y-axis on a special scatterplot that compares predicted values to actual values, to help assess the linearity of the data.
What are residuals?
This is the formula for the slope of the LSRL, solved for r(correlation).
What is r = b (Sx / Sy) ?
Consider the three points (5, 25), (14, 32), (11, 29). Given any straight line, we can calculate the sum of the squares of the three vertical distances from these points to the line.
This is the smallest possible value this sum can be.
What is (25-24.56)2+(32-33.128)2+(29-30.272)2=3.08?