(a) How do the variables in a research study that uses the ordinary Pearson r correlation coefficient differ from the variables in a study that uses the point-biserial correlation coefficient?

(b) Is the procedure for computing a point-biserial correlation coefficient different from the procedure for computing a Pearson r correlation coefficient? Why or why not?

(c) Is the procedure for testing a Pearson r correlation coefficient for statistical significance different from the procedure for testing a point biserial correlation coefficient for statistical significance? Why or why not?

(d) In what way is the meaning of a squared point-biserial correlation coefficient the same as the meaning of any other squared Pearson r correlation coefficient?