# How do I draw scatter plots and find equations of best-fitting lines?

## Presentation on theme: "How do I draw scatter plots and find equations of best-fitting lines?"— Presentation transcript:

How do I draw scatter plots and find equations of best-fitting lines?

7.1 Draw Scatter Plots and Best-Fitting Lines Example 1 Describe and estimate correlation coefficients Describe the data as having a positive correlation, a negative correlation, or approximately no correlation. Tell whether the correlation coefficient for the data is closest to  or  a. Solution a.The scatter plot shows a strong _________ correlation. negative So, the best estimate given is r = ____.

So, r is between ___ and ___, but not too close to either one. The best estimate given is r = _____. 7.1 Draw Scatter Plots and Best-Fitting Lines Example 1 Describe and estimate correlation coefficients Describe the data as having a positive correlation, a negative correlation, or approximately no correlation. Tell whether the correlation coefficient for the data is closest to  or  b. Solution b.The scatter plot shows a weak _________ correlation. positive

7.1 Draw Scatter Plots and Best-Fitting Lines Checkpoint. For the scatter plot, (a) tell whether the data has a positive correlation, a negative correlation, or approximately no correlation, and (b) tell whether the correlation coefficient for the data is closest to   or 1. a.positive correlation b.1 1.

7.1 Draw Scatter Plots and Best-Fitting Lines Checkpoint. For the scatter plot, (a) tell whether the data has a positive correlation, a negative correlation, or approximately no correlation, and (b) tell whether the correlation coefficient for the data is closest to   or 1. a.approximately no correlation b.0 2.

7.1 Draw Scatter Plots and Best-Fitting Lines Example 2 Approximate the best-fitting line The table below gives the number of people y who attended each of the first seven football games x of the season. Approximate the best- fitting line for the data. x1234567 y722763772826815857897 0 1 2 3 4 5 6 7 650 700 750 800 850 900 1.Draw a __________. scatter plot 2.Sketch a best-fitting line. 3.Choose two points on the line. For the scatter plot shown, you might choose (1, ___) and (2, ___). 722 750 4.Write an equation of the line. The line passes through the two points has a slope of:

7.1 Draw Scatter Plots and Best-Fitting Lines Example 2 Approximate the best-fitting line The table below gives the number of people y who attended each of the first seven football games x of the season. Approximate the best- fitting line for the data. x1234567 y722763772826815857897 0 1 2 3 4 5 6 7 650 700 750 800 850 900 Use the point-slope form to write the equation. An approximation of the best-fitting line is

7.1 Draw Scatter Plots and Best-Fitting Lines Checkpoint. Complete the following exercise. 3.The table gives the average class score y on each chapter test for the first six chapters x of the textbook. x123456 y848386888790 0 1 2 3 4 5 6 7 82 84 86 88 90 92 a.Approximate the best-fitting line for the data.

7.1 Draw Scatter Plots and Best-Fitting Lines Checkpoint. Complete the following exercise. 3.The table gives the average class score y on each chapter test for the first six chapters x of the textbook. x123456 y848386888790 0 1 2 3 4 5 6 7 82 84 86 88 90 92 b.Use your equation from part (a) to predict the average class score on the chapter 9 test.

7.1 Draw Scatter Plots and Best-Fitting Lines Pg. 260, 7.1 #1-13

Download ppt "How do I draw scatter plots and find equations of best-fitting lines?"

Similar presentations