Question

In a hospital, weights of new born babies were recorded, for one month. Data is as shown:

Weight of new born baby (in kg)	1.4 - 1.8	1.8 - 2.2	2.2 - 2.6	2.6 - 3.0
No of babies	3	15	6	1

Then the median weight is?

विकल्प

• 2kg

• 2.03kg

• 2.05kg

• 2.08kg

Answer 1

2.05kg

Explanation:-

Construct a table as follows:

Class interval	Frequency (fi)	Midpoint (xi)	Cumulative Frequency (cf)
1.4 - 1.8	3	1.6	3
1.8 - 2.2	15	2	18
2.2 - 2.6	6	2.4	24
2.6 - 3.0	1	2.8	25

Since `N/2=25/2=12.5`

12.5 is near to cumulative frequency value 18

So median class interval is 1.8 - 2.2

∴ Median = `l + [(N/2 - cf)/f]/h`

Here

l = 1.8

`N/2=25/2`

`=>N/2=12.5`

cf = 3

f = 15

h = 0.4

Therefore,

`"Median" = l+[(N/2-cf)/f]h`

`=1.8+[(12.5-3)/15]0.4`

= 1.8 + 0.25

= 2.05

Hence median weight is 2.05 kg.