The Following Data Represent the Test Scores of Eight Students

The following data represent the test scores of eight students on a statistics test before and after attending extra help sessions for the test. $$\begin{array} { | l | c | c | } \hline \text { Student } & \text { Before } & \text { After } \\\hline \text { Abby } & 82 & 90 \\\hline \text { Brenda } & 75 & 86 \\\hline \text { Carmen } & 90 & 90 \\\hline \text { David } & 68 & 62 \\\hline \text { Edward } & 87 & 89 \\\hline \text { Frank } & 73 & 75 \\\hline \text { Gill } & 81 & 78 \\\hline \text { Heidi } & 92 & 98 \\\hline\end{array}$$ Uses the Wilcoxon signed rank sum test to determine at the 5% significance level whether the extra help sessions have been effective.