In Chapter 10 presented data demonstrating that participants who binge-watched a television series enjoyed the show less than participants who watched the series in daily sessions. In the study, one group watched the complete television series in a single session and the other group watched the show in daily, one-hour sessions. After watching the series, each group rated their enjoyment of the series on a scale of 0–100.

a. Convert the data from this problem into a form suitable for the point-biserial correlation (use 1 for the binge-watching participants and 0 for participants who watched the show in daily sessions), and then compute the correlation.

b. Square the value of the point-biserial correlation to obtain r² .

c. The t test in Chapter 10 produced t = 22.94 with df = 8. Use the equation on page 505 to compute the value of r² directly from the t statistic and its df. Within rounding error, the value of r² from the equation should be equal to the value obtained from the point-biserial correlation.