Correlation and Best Fit Lines

Front

What is correlation?

Back

Correlation is a statistical measure that describes the extent to which two variables change together. A positive correlation means that as one variable increases, the other also increases, while a negative correlation means that as one variable increases, the other decreases.

Front

What is a best fit line?

Back

A best fit line, or trend line, is a straight line that best represents the data on a scatter plot. It shows the general direction of the data points and can be used to make predictions.

Front

How do you determine the slope of a line?

Back

The slope of a line is determined by the formula (change in y) / (change in x). It indicates how much y changes for a unit change in x.

Front

What does a slope of 0 indicate?

Back

A slope of 0 indicates that there is no change in y as x changes, meaning the line is horizontal and there is no correlation between the variables.

Front

What does a positive slope indicate?

Back

A positive slope indicates a positive correlation between the two variables, meaning that as one variable increases, the other variable also increases.

Front

What does a negative slope indicate?

Back

A negative slope indicates a negative correlation between the two variables, meaning that as one variable increases, the other variable decreases.

Front

What is the purpose of a scatter plot?

Back

A scatter plot is used to visually display the relationship between two quantitative variables. It helps to identify patterns, trends, and correlations.

Front

What does it mean if points on a scatter plot are widely scattered?

Back

If points on a scatter plot are widely scattered, it indicates a weak or no correlation between the variables.

Front

How can you use a trend line to make predictions?

Back

You can use a trend line to make predictions by extending the line beyond the existing data points to estimate values for new data.

Front

What is the significance of the y-intercept in a linear equation?

Back

The y-intercept is the value of y when x is 0. It represents the starting point of the line on the y-axis.