Question 14(ii)
50 students enter for a school javelin throw competition. The distance (in metres) thrown are recorded below :
Distance (inm)0−2020−4040−6060−8080−100Number of students 6 11 17 12 4
(ii) Draw a cumulative frequency curve (less than type) and calculate the median distance thrown by using this curve.
Distance (in m)Cumulative frequency(cf)0 0Less than 20 6Less than 40 17Less than 60 34Less than 80 46Less than 100 50
To draw less than type ogive. we plot the points (0,0),(20,6),(40,17),(60,34),(80,46),(100,50), join all these points by free hand.
Now, N2=502=25
Taking Y=25 on Y-axis and draw a line parallel to X-axis, which meets the curve at point A. From point A, we draw a line perpendicular to X-axis, where this meets that point is the required median i.e.49.4.