Sample size to detect a significant difference between 2 means with equal sample sizes and variances
Enter Mean in population 1
Enter Mean in population 2
Enter Common Standard Deviation
Enter Ratio of Sample Size required for 2 groups ( Generally it is 1 for keeping equal sample size for two groups )
Select Confidence Interval
80%
90%
95%
99%
Select Desired Power
80%
90%
95%
99%
Use 1 or 2-tailed test
1 tailed
2 tailed
Result
Sample size (per group)
Total sample size (both groups)
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