Question

How to calculate standard deviation with mean and sample size?

Answer 1

⊕ANSWER⊕

Sample Standard Deviation

• Work out the mean.

• Then for each number: subtract the Mean and square the result.

• Then work out the mean of those squared differences.

• To work out the mean, add up all the values then divide by the no: of observations.

• Take the square root of that

SAMPLE SIZE

• But just so you know the math behind it, here are the formulas used to calculate sample size:

• Sample Size Calculation: Sample Size = (Distribution of 50%) / ((Margin of Error% / Confidence Level Score)Squared)

• Finite Population Correction: True Sample = (Sample Size X Population) / (Sample Size + Population – 1)