A Statistics Course Co-Ordinator Has Decided to Incorporate Team Based

A statistics course co-ordinator has decided to incorporate team based learning in tutorials. Each tutorial class of 30 students are grouped into 5 teams of 6 members each. The teams have one group project which is assessed out of 30 marks. There are three tutorial classes in this statistics course, with 5 teams each. Each tutorial class is taught by a different tutor. Each tutor marks their team's projects. The course coordinator wants to ascertain if marking is consistent by the three different tutors. The course coordinator has tabled each teams mark by tutor so as to conduct a Kruskal-Wallis test to determine whether there is enough evidence at the 10% significance level to infer that at least two of the populations represented by the samples below differ. That is, use this test to determine if at least two of the tutor's marks for team's projects differ. $$\begin{array} { | c | c | c | } \hline & { \text { Sample } } \\\hline \text { Tutor A } & \text { Tutor B } & \text { Tutor C } \\\hline 23 & 28 & 20 \\\hline 22 & 27 & 22 \\\hline 25 & 27 & 19 \\\hline 20 & 19 & 21 \\\hline 18 & 20 & 20 \\\hline\end{array}$$