Enter σ1 Enter σ2 Enter Reliability % Enter Variability %

##### How does the Sample Size Requirement for the Difference of Means Calculator work?
Free Sample Size Requirement for the Difference of Means Calculator - Given a population standard deviation 1 of σ1, a population standard deviation 2 of σ2 a reliability (confidence) value or percentage, and a variation, this will calculate the sample size necessary to make that test valid.
This calculator has 4 inputs.

### What 2 formulas are used for the Sample Size Requirement for the Difference of Means Calculator?

n = Z-scoreα/22 x (σ12 + σ22)/SE2
α = 1 - Confidence%

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##### What 4 concepts are covered in the Sample Size Requirement for the Difference of Means Calculator?
confidence interval
a range of values so defined that there is a specified probability that the value of a parameter lies within it.
reliability
the overall consistency of a measure
sample size
measures the number of individual samples measured or observations used in a survey or experiment.
sample size requirement for the difference of means