Seminar: Regression and Correlation
Before to start the activity check the boxes to display the correlation value and the equation of the best- fit line. 1- Arrange the data points to get a strong positive correlation between the variables. Copy your graph and paste it on a word document. (Edit/Graphic View to clipboard). Send the document to your instructor by e-mail. 2- Move the points to get dispersed and concentrated distributions and notice the effect in the correlation value. 3- Arrange the points to get a correlation factor close to -0.80. Then, move the points in the way that the correlation factor remains constant but the equation of the line changes. 4- Rearrange the points to get different correlation values for the same best- fit line. Notice the relationship between the spread of the points, the correlation factor, and the parameters of the equation of the line and use your observations to answer the questions below the graph.
The following questions will be discussed during the seminar: 1- Explain what happen to the correlation factor value when the dispersion between the points increases. 2- What is the relationship between the correlation factor and the slope of the best - fit line? 3- Describe the effect, if any, of the change of the correlation value on the y- intercept of the best- fit line.