Average of \(\mathrm{X} 1, \mathrm{X} 2, \mathrm{X} 3\) and \(\mathrm{X} 4=16\)
$$
\begin{array}{l}
\Rightarrow \frac{X 1+X 2+X 3+X 4=16}{4} \\
\Rightarrow X 1+X 2+X 3+X 4=(16 X 4)=64
\end{array}
$$
and half the sum of \(X_{2}, X_{3}, X_{4}=23\)
\(\Rightarrow \frac{X 1}{4}+\frac{(X 2+X 3+X 4)}{4}=16\)
Multiply through by 2
\(\Rightarrow X 1+\frac{(X 2+X 3+X 4)}{2}=32\)ut \(\frac{X_{2}+X_{3}+X_{4}}{2}=23\)
\(\Rightarrow \frac{X_{L}}{2}=+23=32\)
\(\frac{X_{1}}{2}=9 \Rightarrow X_{1}=18\)