The mean deviation about the mean for the following data:
What is the range of the following data?
23, 45, 34, 21, 89, 45, 47, 91
Maximum and minimum value of the data 23, 45, 34, 21, 89, 45, 47, 91 are 21 and 91.
Range = 91 – 21 = 70
The mean deviation about the mean for the following data:
The mean deviation about the mean for the following data:
The mean deviation about the mean for the following data:
5, 6, 7, 8, 6, 9, 13, 12, 15 is:
let, X =5,6,7,8,9,13,12,15.
(5+6+7+8+9+13+12+15)÷9 = 9.
and hence a = 9.
the mean deviation about the mean is summation of Xa÷ the total number
i.e , Xa = 4,3,2,1,3,0,4,3,6 and the total no. is 9.
hence summation of Xa = 26,
the mean deviation is 26 ÷ 9 = 2.89 ans
For ungrouped data, mean deviation about mean is =
. ……. about a central value ‘a’ is the mean of the absolute values of the deviations of the observations from ‘a’.
The mean deviation of the following data 14, 15, 16, 17, 13 is:
Here N= 5 , sigma x = 75
so mean = 15
now taking deviation from mean,( By ignoring signs)
we get sigma deviation from mean = 6
Now applying the formula of mean deviation
M.D.= SIGMA deviation from mean/ n
so M.D.= 6/5
= 1.2
The mean deviation about the mean for the following data 3, 7, 8, 9, 4, 6, 8, 13, 12, 10 is:
Arrange data in ascending order,
3,4,6,7,8,8,9,10,12,13
No. of observations = 10
Median = n/2 => 10/2 = 5h observation.
5th observation is 8
Now we calculate mean deviation about median, i.e;
=> ∑∣xi−M∣/10
= {38 +48 +68 +78 +88 +88 +98 +108 +128 +138 }/10
= { 5 + 4 + 2 + 1 + 0 + 0 + 1 + 2 + 4 + 5}/10
= 24/10 => 2.4
The arithmetic mean of the numerical values of the deviations of items from some average value is called the
Mean deviation of a data set is the average of the absolute deviations from a central point (Average value).
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