unit 2 stats

Two-Way Table

A table displaying qualitative data from two categorical variables, often called a contingency table.

Marginal Frequencies

Totals for each row and column in a two-way table, placed in the margins.

Correlation Coefficient

A numerical measurement indicating the strength of a linear relationship between two quantitative variables.

Coefficient of Determination (r^2)

The ratio of the variance of predicted values to the variance of observed values, explaining the percentage of variation in the response variable.

Residual

The difference between an observed value and a predicted value in regression analysis.

Outliers

Points in a scatterplot that deviate significantly from the overall pattern, affecting the regression analysis.

Influential Scores

Scores that, if removed, would significantly alter the regression line, often due to extreme x-values.

Leverage

The potential of a point to change the regression line, especially if its x-value is far from the mean x-value.

Regression Equation

The equation representing the best-fitting straight line through a set of points in a scatterplot.

Standard Deviation Increase

The change in predicted y-value for each standard deviation increase in x, based on the correlation coefficient.

Regression Equation

An equation used to predict one variable based on another, with the slope representing the change in the predicted variable for a unit change in the predictor variable.

Transformations

Altering the form of variables to achieve a linear relationship, often by using logarithmic functions like log or ln.

Variability

The extent to which data points differ from the mean or predicted values, indicating the spread or dispersion of the data.

Linear Model

A model that assumes a straight-line relationship between variables, explaining a certain percentage of variability in the data.

Nonlinear Relationship

A relationship between variables that cannot be adequately represented by a straight line, suggesting the need for a curved model to better explain the data.