An introduction to t tests for one population mean. I briefly discuss when we use the test, and when we would use a z test instead. I also briefly discuss the hypotheses of the test, and the p-value for different alternatives. I then work through an example. (If you are comfortable with the basics of hypothesis testing, and understand the difference between t and z procedures from confidence intervals, then much of this video may be review.) If you are just looking for an example, it starts at 7:00.
The reaction time data is simulated data with the same summary statistics as found in:
Armstrong et al. (2012). Mild Dehydration Affects Mood in Healthy YoungWomen.
Journal of Nutrition, 142: 382–388.