Find the mean, median and mode of the following data:


Classes:



0-20



20-40



40-60



60-80



80-100



100-120



120-140



Frequency:



6



8



10



12



6



5



3



Class interval



Mid value(x)



Frequency(f)



fx



Cummulative frequency



0-20



10



6



60



6



20-40



30



8



240



14



40-60



50



10



500



24



60-80



70



12



840



36



80-100



90



6



540



42



100-120



110



5



550



47



120-140



130



3



390



50



Total




N=50





Mean= =


We have, N= 50,


N/2 = 25


Hence, median class =60-80, such that


l=60, f’=12, f=24, h=20


Median = l +


Here, we may observe that maximum class frequency is 12 belonging to the class interval 60-80


So, modal class= 60-80


Lower limit, l= 60


f0=10, f2=6, f=12,h = 20



=


15