Draw ogive for the data given below and from the graph determine:
(i) the median marks.
(ii) the number of students who obtained more than 75% marks. $$\begin{tabular}{|l|l|l|l|l|l|l|l|l|l|} \hline Marks & $10-$ & 20 & $30-$ & $40-$ & $50-$ & $60-$ & $70-$ & $80-$ & $90-$ \\ \hline & 19 & $-29$ & 39 & 49 & 59 & 69 & 79 & 89 & 99 \\ \hline No. of students & 14 & 16 & 22 & 26 & 18 & 11 & 6 & 4 & 3 \\ \hline \end{tabular}$$

Solution:
$$\begin{tabular}{|l|l|l|}
\hline Marks & No. of students & Cumulative frequency \\
\hline $9.5-19.5$ & 14 & 14 \\
\hline $19.5-29.5$ & 16 & 30 \\
\hline $29.5-39.5$ & 22 & 52 \\
\hline $39.5-49.5$ & 26 & 78 \\
\hline $49.5-59.5$ & 18 & 96 \\
\hline $59.5-69.5$ & 11 & 107 \\
\hline $69.5-79.5$ & 6 & 113 \\
\hline $79.5-89.5$ & 4 & 117 \\
\hline $89.5-99.5$ & 3 & 120 \\
\hline
\end{tabular}$$
Scale:
$1 \mathrm{~cm}=10$ marks on $\mathrm{X}$ axis
$1 \mathrm{~cm}=20$ students on $\mathrm{Y}$ axis

(i) Therefore, the median $= 120/ 2 = 60^{th}$ term

Draw a parallel line to $x-axis$ through mark $60$ which meets the curve at A. Now from A, draw a perpendicular to $x-axis$ meeting it at B.

Value of point B is the median $= 43$

(ii) Total marks $= 100$

75% of total marks $= 75/100 \times 100 = 75$ marks

As a result, the no. of students getting more than 75% marks $= 120 {–} 111 = 9$ students.