This formula is used to compute the average of the data collected. E X 1 n n m m We have shown that the mean or expected value if you prefer of the sample mean X is m. For a sample size of more than 30 the sampling distribution formula is given below.
How to find Sample Mean and Population mean.
The mean is now x for sample mean instead of m the population mean And the answer is s for Sample Standard Deviation instead of s. This formula can be used when you know and want to determine the sample size necessary to establish with a confidence of the mean value to within You can still use this formula if you dont know your population standard deviation and you have a small sample size. Using mathematical notation if a sample of N observations on variable X is taken from the population the sample mean is. Sum_ i1 nx_ i x 1 x 2 x n.