Compare Means use parametric methods. Parametric implies that a distribution is assumed for the population. Often, an assumption is made when performing a hypothesis test that the data are a sample from a certain distribution, commonly the normal distribution.

•One-sample t Test

Tests whether the mean of a single variable differs from a specified constant.

•Two-Sample t Test

Tests whether two samples from a normal distribution could have the same mean when the standard deviations are unknown but assumed to be equal.

•One-Sample Z Test

Determines whether a sample from a normal distribution with known standard deviation could have a given mean.

•Two-Sample Paired t Test

Tests the null hypothesis that the population mean of the paired differences of two samples is zero.

•Two-Sample F Test

Tests if the variances of two populations are equal.