The table given below shows the frequency distribution of the scores obtained by 200 candidates in a BCA entrance examination.

Draw cumulative frequency curves by using ( i) 'less than' series and (ii) 'more than' series.
Hence, find the median

Explanation

Less Than Series:
We may prepare the less than series as under.


Scale: `{("Along the x-axis, 1 small div,=5"),("Along the y-axis , 1 small div,=2"):}`
We plot the points A(250, 30), B(300, 45), C(350, 90), D(400, 110), E(450, 135), F(500, 175), G(550, 185) and H(600, 200) on a graph paper.
Join AB, BC, CD, DE, EF, FG and GH freehand to get the curve representing 'Less Than Series'.
(ii) More Than Series:
We may prepare the more than series as under


Now, on the same graph paper as above, we plot the points P(200, 200), Q(250, 170), R(300, 155), 5(350, 110), T(400, 90), U(450, 65), V(500, 25), W(550, 15).
Join PQ, QR, RS, ST, TU, UV and VW freehand to get the curve representing 'More Than Series'.
The two curves intersect at the points L. Draw LM `bot` OX cutting the x-axis at M


Clearly , M represents 375
Hence , median =375