(a) How do the variables in a research study that uses the ordinary Pearson 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 correlation coefficient? Why or why not? (C) Is the procedure fortesting a Pearson 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 square point-biserial correlation coefficient the same as the meaning of any other squared Pearson correlation coefficient