SCATTER PLOTS A Scatter Plot is a graph that relates two set of data by plotting ordered pairs. Scatter plots can be used to determine the “strength” of the relationship between data sets, this is called correlation.
MAKING A SCATTER PLOT1. Decide which variable is the independent variable (x) and which is the dependent variable (y).2. Create axes in the appropriate units based on your table of values (remember if you do not start an axis at zero you need to use the changing scale symbol)3. Plot points4. Look for correlation
EXAMPLE: PAGE 93 The table lists average monthly temperature and electricity costs for a home in Texas in 2008. The table displays the values. Make a scatter plot. How would you describe the correlation?
TREND LINE A trend line is a line that approximates the relationship between the variables or data sets. Can be used to make predictions To find the equation of the trend line: 1. Create the scatter plot 2. Sketch the trend line 3. Choose two points on the sketch for step 2 4. Write an equation of a line for the two points chosen