Formula To Find Minimum Sample Size. The formula does not cover finite population. 1 001 001 2 38032 Rounding up this tells us that 381 low-risk customers will need to be sampled.
Sigma σ is provided and the significance level is specified we can compute the minimum required sample size that will lead to a margin of error less than or equal to the one specified by using the following formula. N zsE2 Where n is the sample size z is the z value for the level of confidence chosen s is the estimated standard deviation and E is the allowable error. Plug in your Z-score standard of deviation and confidence interval into the sample size calculator or use this sample size formula to work it out yourself.
Using Cochrans Formula we can calculate the minimum sample size for this test as.
Determine the confidence interval. You can do this by using a formula or by finding a sample size calculator online. If we are using three independent variables then a clear rule would be to have a minimum sample size of 30. Sample Size n N Z2 p 1-pe2 N 1 Z2 p 1-pe2.
