Cheat Sheet Basic Statistics Formulas. Moe represents the desired margin of error. These formulas reference include the basic functions of mean mode median sample size variance standard deviation standard error z score margin of error confidence interval covariance correlation coefficient probability regression permutations combinations normal distribution binomial distribution poisson distribution exponential distribution uniform distribution triangular distribution gamma distribution weibull distribution normal distribution f distribution t.
To find the sample size needed to estimate a population mean or a population proportion p use the following formula. Limits for unusual data below. µ σ σ.
Moe represents the desired margin of error.
Z is the critical value for the confidence level you need. If σ is unknown you can estimate it with the sample standard deviation s from a pilot study. Range highest value lowest value sample standard deviation. In this formula moe represents the desired margin of error which you set ahead of time and σ represents the population standard deviation.
