Applied Statistics

Sample Mean Let the random variables X1, X2,……….,Xn  denote a random sample from a population. The sample mean value of these random variab...

Statement Let X1, X2,……….,Xn  be a set of n independent random variables having identical distribution with mean  and variance  , and with...

Let X be the number of success in a binomial sample of n observations with parameter P. The parameter is the proportion of the population me...

Sample Variance Let  x 1 , x 2, ……..,x n   be a random sample of observations from a population. The quantity  is called the sample var...

We often use samples instead of the entire population because the cost and time of measuring every item in the population would be prohibiti...

To use stratified sampling, we divide the population into relatively homogeneous groups, called strata. Then we use one of two approaches. E...

Consider a random sample selected from a population that is used to make an inference about some population characteristic, such as the popu...