AP stats chapter 3 terms

Definitions and interpretations

r

correlation

Standard deviation of the residuals “s”

the size of a typical residual, typical distance between the actual y values and the predicted y values.

Interpretation of “s”

The actual (y) is typically about # away from the (y) predicted by the least-squares regression line when x=(x)

Coefficient of determination “r²”

measures the percent of the variability in the response variable that is accounted for by the least squares regression line.

Interpretation of “r²”

About #% of the variability in (y) is accounted for by the least-squares regression line with x=(x).

High leverage

much larger or much smaller x values than the other points in the data set.

Outlier

does not follow the pattern of the data and has a large residual.

Influential point

If removed, substantially changed the slope, y intercept, correlation, coefficient of determination, or standard deviation of the residuals.

Linear (transformation)

x, y

Power (transformation)

lnx, lny

Exponential (transformation)

x, lny