(Q3) During the medical check-up of 35 students of a class, their weights were recorded as follows:

Weight (in kg)	Number of students
Less than 38	0
Less than 40	3
Less than 42	5
Less than 44	9
Less than 46	14
Less than 48	28
Less than 50	32
Less than 52	35

Draw a less than type ogive for the given data.

Hence obtain the median weight from the graph and verify the result by using the formula.

Answer :

Upper limits of the classes and less than cumulative frequencies. Therefore required points are (38, 0), (40, 3), (42, 5), (44, 9), (46, 14), (48, 28), (50, 32) and (52, 35).

X-axis - upper limits 1 cm = 2 units.

Y-axis - less than c.f. 1 cm = 4 units.

Number of observations =

Locate the point on the ogive whose ordinate is .

The x - coordinate of this point is the required median.

From the graph, median = 46.5.

Weight	Number of students	Frequency
Below 38	0
38-40	3
40-42	5
42-44	9
44-46	cf 14
46-48 (l)	f 28
48-50	32
50-52	35

17.5 belongs to the class 46-48

Median class = 46-48

l-lower boundary of class =

f-frequency of the median class =14

c.f = 14 , Class size = 2

Median = + =

Here median is by either by ways.