Question
Mon March 12, 2012 By:
for the following data
  xi  3 6 9 12 13 15 21 22
  fi   3  4 5 2 4 5 4 3

find the mean deviation about median?

Expert Reply
Tue March 13, 2012
median = mean of { 15th term and 16th term } 
we need to calculate cummulative frequence to make the problem simpler , as without that we will have to write 30 numbers and then look for 15th and 16th term in the series of numbers .
 
here median = 13 ,  deviation = (x - A) , x is the value of data , A is the median about which mean deviation is to be calculated
 
= -10 , -7 , -4 , -1 , 0 , 2 , 8 , 9 
mean deviation = sigma(f.devaition)/sigma(f) = (-30 -28 -20 -2 + 0 +10+32+27)/30 = -11/30
Ask the Expert