Chapter 3 Stats Review - Two-Variable Data

Front

What is correlation?

Back

Correlation is a statistical measure that describes the extent to which two variables change together. It can be positive, negative, or zero.

Front

What is positive correlation?

Back

Positive correlation occurs when an increase in one variable leads to an increase in another variable.

Front

What is negative correlation?

Back

Negative correlation occurs when an increase in one variable leads to a decrease in another variable.

Front

What does 'no correlation' mean?

Back

No correlation means that there is no relationship between the changes in two variables.

Front

What is causation?

Back

Causation indicates that one event is the result of the occurrence of another event.

Front

Give an example of causation.

Back

If it starts raining, the baseball game is delayed. The rain caused the delay.

Front

What is the slope in a least squares line equation?

Back

The slope represents the rate of change of the response variable for each unit change in the explanatory variable.

Front

Interpret the slope: For each additional 1 hour worked, income increases by $31.45.

Back

This means that for every extra hour a person works, their income is expected to increase by $31.45.

Front

What is a residual plot?

Back

A residual plot is a graph that shows the residuals on the vertical axis and the independent variable on the horizontal axis.

Front

What should a good residual plot look like?

Back

A good residual plot should show a random scatter of points, indicating that the model is appropriate.