Read this article to learn how to Calculate Standard Deviation in 3 different Series!
A. Individual Series:
Deviation can be taken from Actual Mean and following formula is used.
Here also the deviations can be taken from Actual or Assumed Mean.
From Actual Mean:
Where x2 is the square of deviations from actual mean, f denotes corresponding frequency; N = ∑ f
C. Continuous Series:
Here we take the deviations from Actual or Assumed Mean as desired from the Mid Point of Class-Intervals.