Minimum sample size calculator

1. What is the minimal sample size needed for a 95 %?
2. Why is 30 the minimum sample size?
3. When sample size is less than 30 which can be used?

What is the minimal sample size needed for a 95 %?

A sample size of 385 corresponds with a confidence level of 95% and margin of error of 5% when you have a large population (> 100,000), which is often used in research.

Why is 30 the minimum sample size?

A sample size of 30 often increases the confidence interval of your population data set enough to warrant assertions against your findings.4 The higher your sample size, the more likely the sample will be representative of your population set.

When sample size is less than 30 which can be used?

For example, when we are comparing the means of two populations, if the sample size is less than 30, then we use the t-test.