CK-12 Foundation
Ck 12: Algebra Ii: 6.6 the T Test
Learn about a statistical test that is used to compare the means of two groups, the T Test.
Wolfram Research
Wolfram Math World: Paired T Test
A brief explanation on what the paired T-Test is. Equations are given for its computation.
Other
Westgard Qc: A Note About the "Paired T Test" in Method Comparison
A note about paired t-tests within a larger article dealing with hypothesis testing.