We observe that the number of packets less than 200 is 0. Similarly, less than 201 includes the number of pacakets from 0-200 as well as the number of packets from 200-201. So, the total number of packets less than 201 is 0+13=12. We say that , the cumulative frequency of the class 200-201 is 13. Similarly for other class.
To draw the less than type ogive we plot the points (200,0), (201,13),(202,40),(203,58),(204,68),(205,69) and (206,70) on the paper and join by free hand.
`therefore` Total number of packets(n)=70
Now, Firstly, we plot a point (0,35) on Y-axis and draw a line =35 parallel to X-axis. The line cuts the less than ogive curve at a point. We draw a line on that point which is perpendicular to x-axis. The foot of hte perpendicular to X-axis is the required meidan.
`therefore` Median weight=201.8g
