Question

A survey reagarding the heights ( in cm) of 50 girls of class X of a school was conducted and the following data was obtained.

Find the mean, median and mode of the above data.

Answer 1

(i) Mean : Mean =(Sigmaf_(i)x_(i))/(Sigmaf_(i)) =7490/50 =149.80`
(ii) Median : Here, `N/2=50/2 =25`
`:.` Median class is 150 -160
`:.` Median `=l_(1)+((N/2-C))/fxxi`
`=150+(25-22)/20xx10`
`=150+1.5=151.5`
(iii) Mode : Clearly the modal class is 150-160 as it has the maximum frequency
Mode =`l+((f_(1)-f_(0))/(2f_(1)-f_(0)-f_(2)))xxh`
`=150+((20-12)/(40-12-8)) xx10`
`=150+8/20xx10`
=150+4=154
Hence, the mean height of the girls =149.80 cm
the median height =151.5 cm
and the modal height =154 cm