5 Georgio has designed two new uniforms $X$ and $Y$ for the employees of an airline company. A random sample of 11 employees are each asked to assess each of the two uniforms for practicality and appearance, and to give a total score out of 100. The scores are given in the table.

\begin{center}
\begin{tabular}{ | l | c | c | c | c | c | c | c | c | c | c | c | }
\hline
Employee & $A$ & $B$ & $C$ & $D$ & $E$ & $F$ & $G$ & $H$ & $I$ & $J$ & $K$ \\
\hline
Uniform $X$ & 82 & 74 & 42 & 59 & 60 & 73 & 94 & 98 & 62 & 36 & 50 \\
\hline
Uniform $Y$ & 78 & 75 & 63 & 56 & 67 & 82 & 99 & 90 & 72 & 48 & 61 \\
\hline
\end{tabular}
\end{center}

(a) Give a reason why a Wilcoxon signed-rank test may be more appropriate than a $t$-test for investigating whether there is any evidence of a preference for one of the uniforms.\\

(b) Carry out a Wilcoxon matched-pairs signed-rank test at the $10 \%$ significance level.\\

\hfill \mbox{\textit{CAIE Further Paper 4 2021 Q5}}