# 0-4 2 4-8 4 8-12 7 12 - 16 5 16-20 8 20 -24 3 24 - 28 2 28 -32 1 32 - 36 13 36 - 40 5 40 -44 3 44 - 48 3 find the median . also use ogives

 Class Interval Frequency (f) Cumulative Frequency (CF) 0-4 2 2 4-8 4 6 8-12 7 13 12-16 5 18 16-20 8 26 20-24 3 29 24-28 2 31 28-32 1 32 32-36 13 45 36-40 5 50 40-44 3 53 44-48 3 56

Median = Size of th item

N = 56

Þ Median = Size of th item

= Size of 28th item

This corresponds to 26th cumulative frequency and the median class is (20-24)

l = 20,  CF = 26,  f = 3

Ogive Method

Converting the series into Less than cumulative frequency.

 Commutative Frequency (CF) Coordinates ofLess than Ogive Less than 4 2 (4, 2) Less than 8 6 (8, 6) Less than 12 13 (12, 13) Less than 16 18 (16, 18) Less than 20 26 (20, 26) Less than 24 29 (24, 29) Less than 28 31 (28, 31) Less than 32 32 (32, 32) Less than 36 45 (36, 45) Less than 40 50 (40, 50) Less than 44 53 (44, 53) Less than 48 56 (48, 56)

Converting the series into More than cumulative frequency

 Commutative Frequency (CF) Coordinates of More than Ogive More than 0 56 (4, 2) More than 4 54 (8, 6) More than 8 50 (12, 13) More than 12 43 (16, 18) More than 16 38 (20, 26) More than 20 30 (24, 29) More than 24 27 (28, 31) More than 28 25 (32, 32) More than 32 24 (36, 45) More than 36 11 (40, 50) More than 40 6 (44, 53) More than 44 3 (48, 56)

So, graphically Median is determined where both Less than Ogive and More than Ogive curves intersect each other.

• 0
What are you looking for?