Linear Regression Review

Front

What does the correlation coefficient measure?

Back

The strength of the linear relationship between two quantitative variables.

Front

Which statements are TRUE regarding correlation and residuals? I. Random scatter in the residuals indicates a linear model. II. If two variables are very strongly associated, then the correlation between them will be near 1 or -1. III. Changing the units of measurement for x or y changes the correlation coefficient.

Back

I and II only.

Front

What should a residual plot look like for a good linear model?

Back

Random with no pattern.

Front

Interpret the slope of the Least Squares Line Equation: If the slope is $31.45, what does it mean?

Back

For each additional hour, income is predicted to increase by $31.45.

Front

Describe the correlation in a graph that shows a downward trend with points closely clustered along a line.

Back

Strong Negative Linear.

Front

What is linear regression?

Back

A statistical method used to model the relationship between a dependent variable and one or more independent variables.

Front

What is the purpose of a residual plot?

Back

To assess the fit of a linear regression model by showing the residuals on the vertical axis and the independent variable on the horizontal axis.

Front

What does a positive correlation indicate?

Back

As one variable increases, the other variable also tends to increase.

Front

What does a negative correlation indicate?

Back

As one variable increases, the other variable tends to decrease.

Front

What is the least squares method?

Back

A statistical technique used to determine the best-fitting line by minimizing the sum of the squares of the residuals.