Methods and formulas for Paired t

Select the method or formula of your choice.

Confidence interval (CI)

Formula

Notation

TermDescription
sd
Σd / n
d x1 - x2 and x1 and x2 are paired observations from populations 1 and 2, respectively
tα/2 the inverse cumulative probability of a t distribution with n-1 degrees of freedom at 1-α/2
α 1 - confidence level/100
nSample size of the pairs of observations

T-value

Formula

Notation

TermDescription
μ0 hypothesized population mean of the differences
mean of the paired sample differences
sd sample standard deviation of the paired sample differences
nSample size of the pairs of observations

Degrees of freedom (DF)

Applies to: Minitab web app

Formula

Notation

TermDescription
vDegrees of freedom
nSample size of the pairs of observations

P-value

The calculation for the p-value depends on the alternative hypothesis.

Alternative Hypothesis P-value

Notation

TermDescription
μd population mean for the sample of differences
μ0 hypothesized population mean for the sample of differences
tt-statistic of the sample data
tn-1a random variable from the t-distribution with n-1 degrees of freedom
nSample size of the pairs of observations