The royalty gold corporation prospects for undiscovered gold deposits around the world. the company is currently investigating a possible site on the island of milos off the coast of greece in the mediterranean. when prospecting, the company drills to collect soil and rock samples and then analyzes the chemical properties of the samples to determine whether or not the site is likely to contain significant gold deposits. gold is made up of various elements, including calavarite, sylvanite, and petzite. sites with higher concentrations of these elements are more likely to contain significant gold deposits. the company has collected the data found in the file dat10-8.xls that accompanies this book representing the average levels of calavarite, sylvanite, and petzite in samples collected from previous various sites examined in previous prospecting expeditions. these data are grouped according to whether or not significant gold deposits were found at the location (1 = significant, 2 = insignificant).

a. what are the coordinates of the centroids for the two groups?

b. use the regression approach to two-group da to develop a classification rule for predicting whether or not a given site will contain a significant amount of gold. state your classification rule.

c. create a confusion matrix that summarizes the accuracy of your classification rule on the given data. overall, how accurate is your classification rule?