The given data is
38, 70, 48, 40, 42, 55, 63, 46, 54, 44
Mean of the given data,
The deviations of the respective observations from the mean 
are
–12, 20, –2, –10, –8, 5, 13, –4, 4, –6
The absolute values of the deviations,i.e.
, are
12, 20, 2, 10, 8, 5, 13, 4, 4, 6
The required mean deviation about the mean is
