Stat test 1 Linear Regression

Outlier

An individual value that falls outside of the overall pattern of the relationship.

Positive Association

Defined when above-average values of one variable are accompanied by above-average values of the other.

Predicted

y^​ is the predicted value of the y-variable for a given x.

Causation

Important note: Association does not imply this.

Independent Variable

Another name for the x-variable

t-Distribution

To calculate a confidence interval, we must use the standard ___ of the statistic.

Scatterplot

A graphical display of the relationship between two quantitative variables.

Influential Point

A point that substantially changes the estimated regression model or line.

Correlation

Measures the strength and direction of the linear relationship between two quantitative variables.

Residual

Observed y minus predicted y.

Negative Association

Defined when above-average values of one variable are accompanied by below-average values of the other.

Transformation

When data display a curved relationship, we can perform a ___ to straighten it out.

Extrapolation

Using a regression model to make a prediction for values of x outside the observed data range.

Coefficient of Determination (R²)

Indicates the proportion of variability in y that can be explained by the model.

Confidence Interval

Used to estimate the population (true) slope.

Dependent Variable

Another name for the y-variable.

Slope

The amount by which y is predicted to change (on average) when x increases by one unit.