# Calculate Sample Size Worksheets

This worksheet will help you know how to determine the Sample Size. Sample size determination is closely related to statistical estimation. The sample size of a statistical sample is the number of observations that constitute it. It is typically denoted n, a positive integer.
Sample Size formula
Sample = Confidence Level/(Confidential Interval)2
Sample Size = Sample/ [1 + ((sample -1) / P)]
Where
The value of confidential Level is,
90% = 0.680625
95% = 0.9604
99% = 1.664

Sample Size Example
Calculate the Sample Size whose Confidence Level is 90%, Confidential Interval is 35% & population is 95.
Substitute these values in the above formula we get,
Sample = Confidence Level/(Confidential Interval)2
= 90%/(35%)2 [Substitute the value of Confidence Level]
= 0.680625 / (0.35)2
= 5.5561
Sample Size = Sample/ [1 + ((sample - 1) / P)]
= 5.5561 / [1 + (5.5561 - 1)/90]
= 5.5561 / 1.05
= 5.2884

The above worksheet is a sample walk through to understand how to calculate sample size. When you try this calculation on your own, use this sample size calculator to verify your results.