The variable "2013 Cost" represents the four-year cost including tuition, supplies, room and board of attending the school. The variable "Annual ROI" represents the return on investment for graduates of the school. It essentially represents how much you would earn on the investment of attending the school. The variable "Grad Rate" represents the graduation rate of the school.
Go to www.pearsonhighered.com/ sullivanstats to obtain the data file 4_1_47 using the file format of your choice for the version of the text you are using.
(a) Draw a scatter diagram between 2013 Cost and Grad Rate treating 2013 Cost as the explanatory variable. What does the scatter diagram suggest?
(b) Find the linear correlation coefficient between 2013 Cost and Grad Rate. What does this suggest?
(c) Is there a linear association between cost and return on investment? Explain. What does your analysis suggest?