Examine the computation formula for the sample correlation coefficient r [formulas (1) and (2)].
(a) In the formula for r, if we exchange the symbols x and y, do we get a different result or do we get the same (equivalent) result? Explain.
(b) If we have a set of x and y data values and we exchange corresponding x and y values to get a new data set, should the sample correlation coefficient be the same for both sets of data? Explain.
(c) Compute the sample correlation coefficient r for each of the following data sets and show that r is the same for both.

8 1 2 5 2