Em tham khảo nha :
\(\begin{array}{l}
{X_1} = 35 + 44 = 79dvC\\
{n_{{X_2}}} = {n_{{X_1}}} + 2 = 44 + 2 = 46\\
{X_2} = 35 + 46 = 81dvC\\
\% {X_1} = \dfrac{{27}}{{27 + 23}} \times 100\% = 54\% \\
\% {X_2} = 100 - 54 = 46\% \\
{M_{tb}} = \dfrac{{79 \times 54 + 81 \times 46}}{{100}} = 79,92dvC
\end{array}\)