5-7: Scatter Plots & Lines of Best Fit

What is a scatter plot?  A graph in which two sets of data are plotted as ordered pairs  When looking at the graph you can see the relationship between the two variables.  A graph in which two sets of data are plotted as ordered pairs  When looking at the graph you can see the relationship between the two variables.

When we look at relationships of x and y…  There are 3 possibilities  Positive Correlation  Negative Correlation  No Correlation  There are 3 possibilities  Positive Correlation  Negative Correlation  No Correlation

Positive Correlation  As x increases, y increases  Has a positive slope.  As x increases, y increases  Has a positive slope.

Negative Correlation  As x increases, y decreases  Has a negative slope.  As x increases, y decreases  Has a negative slope.

NO Correlation  No relationship between x and y.

Lines of Best Fit  A line which describes the trend of the data.  You will determine the line of best fit, by sketching a line which passes through as many points as possible.  A line which describes the trend of the data.  You will determine the line of best fit, by sketching a line which passes through as many points as possible.

Finding Equations of Lines of Best Fit 1)Plot the data 2)Sketch a line of best fit, passing through as many points as possible. 3)Choose 2 points on your line and find the equation of the line. a) find the slope b) Write the equation of the line in slope intercept form. (y = mx + b) 1)Plot the data 2)Sketch a line of best fit, passing through as many points as possible. 3)Choose 2 points on your line and find the equation of the line. a) find the slope b) Write the equation of the line in slope intercept form. (y = mx + b)

Let’s Do It! Close your laptop and plot the data on the notesheet.