Question

find the median of the dat of class interval 118-126 127-135 136 -144 145 -153 154-162 163-171 172- 180 frequency 3 5 9 12 5 4 2 respectively and also find the median by using the formula of median

Answer 1

median =l+n/2-cf /f ×h

median =145 + ( 20 -17 / 12 ) ×8

median = 145 +2 = 147

Answer 2

Answer:

median = 146.75

Step-by-step explanation:

class interval     frequency   c.f

117.5-126.5          3                   3

126.5-135.5         5                   8

135.5-144.5         9                   17

144.5-153.5         12                  29

153.5-162.5         5                    34

162.5-171.5          4                    38

171.5- 180.5         2                    40

here, $\frac{N}{2}$ = 20

and, cumulative frequency just greater than 20 is 29

corresponding class is 144.5-153.5

thus, median class is  144.5-153.5

$median =l+ \frac{h}{f}( \frac{N}{2} -C)$

lower limit of the median class, l = 144.5

frequency of the median class,f = 12

magnitude of the median class, h = 9

C is the c.f of class preceding the median class = 17

hence, median = $144.5+ \frac{9}{12} (\frac{40}{2} -17)$ = 144.5+ 2.25

            median = 146.75