If the sum of the squares of deviations for 10 observations taken from their mean is 2.5, then write the value of standard deviation.
Given, The sum of the squares of derivations for 10 observation, and mean is 2.5.
To Find: Find the standard derivation
Explanation: Here, N=10 and mean = 2.5
The square of each division = 
Standard deviation 
Hence, standard deviation is 0.5
2