A geologist collected 20 different ore samples, all of the same weight, and randomly divided them into two groups. The titanium contents of the samples, found using two different methods, are listed in the table:

a. Use an appropriate method to test for a significant difference in the average titanium contents using the two different methods.
b. Determine a 95% confidence interval estimate for (µ1 = µ2). Does your interval estimate substantiate your conclusion in part a? Explain.

Method 1 Method 2 011 013 013 015 014 0016 013 012 015 013 010 013 011 012 012 017 013 014 .015