Here, we observe that, the weight of all 70 packets is more than or equal to 200. Since, 13 packets lie in the interval 200-201. So, the weight of 70-13=57 packets is more than or equal to 201. Continuing in this manner we will get remaining more than or equal to 202, 203,204,205 and 206.
Weight (in g)Number of packetsNumber of packetsNumber of studentsLess than 200 0More than or equal to 20070Less than 201 13More than or equal to 20170−13=57Less than 202 40More than or equal to 20257−27=30Less than 203 58More than or equal to 20330−18=12Less than 204 68More than or equal to 20412−10=2Less than 205 69More than or equal to 2052−1=1Less than 206 70More than or equal to 2061−1=0 To draw the less than type ogive, we plot the points (200,0),(201,13),(202,40),(203,58),(204,68),(205,69),(206,70) on the paper and join them by free hand.
To draw the more than type ogive plot the points (200,70),(201,57),(202,30),(203,12),(204,2),(205,1),(206,0) on the graph paper and join them by free hand.
The abscissa(x-coordinate) where the two graphs meet is median =201.8 g