Formula To Find Minimum Sample Size. 1 001 001 2 38032 Rounding up this tells us that 381 low-risk customers will need to be sampled. N ge left frac z_c sigma Eright2 n E zc.
This equation is for an unknown population size or a very large. Necessary sample size Z-score2 standard deviation 1 - standard deviation margin of error2. N ge left frac z_c sigma Eright2 n E zc.
Determine the confidence interval.
Determine the population size if known. 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. Necessary sample size Z-score2 standard deviation 1 - standard deviation margin of error2. This equation is for an unknown population size or a very large.
