An incomplete frequency distribution is given below:
\begin{tabular}{|l|c|c|c|c|c|c|c|}
\hline Height (inches) & $5.1-6.0$ & $6.1-7.0$ & $7.1-8.0$ & $8.1-9.0$ & $9.1-10.0$ & $10.1-11.0$ & $11.1-12.0$ \\
\hline No. of Plants & 3 & 8 & 27 & $?$ & 17 & 11 & 9 \\
\hline
\end{tabular} It is known that the median height of the plant is $8.53$ inches. Calculate the $\begin{array}{ll}\text { missing frequency. } & \text { [I.C.W.A., Jan. '72] }\end{array}$