Testing for the difference of two population means

We can do a significance test to judge if the difference between two means is significant (unlikely to occur by chance alone). For example, a chain of restaurants might want to test to see if there is a difference in the average portion size between two of their locations.

Hypotheses for a two-sample t test

Example of hypotheses for paired and two-sample t tests

Writing hypotheses to test the difference of means

Two-sample t test for difference of means

Test statistic in a two-sample t test

P-value in a two-sample t test

Conclusion for a two-sample t test using a P-value

Conclusion for a two-sample t test using a confidence interval

Making conclusions about the difference of means