Ten Business People Who Fly Frequently from Melbourne to Sydney

Essay

Ten business people who fly frequently from Melbourne to Sydney were asked to rank four airlines in terms of the quality of service. The people assigned scores using a 5-point Likert scale where: 1 = bad, 2 = poor, 3 = average, 4 = good, and 5 = excellent. The results are shown below. $\begin{array} { | c | c | c | c | c | } \hline & & { \text { Airline } } \\\hline \text { Person } & \text { A } & \text { B } & \text { C } & \text { D } \\\hline 1 & 5 & 5 & 2 & 1 \\\hline 2 & 3 & 3 & 4 & 2 \\\hline 3 & 2 & 3 & 4 & 3 \\\hline 4 & 1 & 1 & 4 & 3 \\\hline 5 & 4 & 1 & 5 & 3 \\\hline 6 & 2 & 3 & 4 & 2 \\\hline 7 & 1 & 3 & 5 & 2 \\\hline 8 & 3 & 3 & 5 & 1 \\\hline 9 & 1 & 3 & 5 & 2 \\\hline 10 & 2 & 4 & 3 & 1 \\\hline\end{array}$ Can we conclude at the 5% significance level that there are differences in service quality among the four airlines?