Question

Find the mean deviation about the mean for the mean for the following data :
15, 17, 10, 13, 7, 18, 9, 6, 14, 11

Answer 1

Let the mean of the given data be `barx.` Then,
`barx=(overset(n)underset(i=1)Sigmax_(i))/(n)=(120)/(10)=12" "[because n=10].`
The values of `(x_(i)-barx)` are :
3,5,-2,1,-5,6,-3,-6,2,-1.
So, the values of `|x_(i)-barx|` are :
3,5,2,1,5,6,3,6,2,1.
`therefore" "MD(barx)=(overset(n)underset(i=1)Sigma|x_(i)-barx|)/(n)=(34)/(10)=3.4.`
Hence, MD `(barx)=3.4.`