November 13, 2003
Where is theta?
The point of today's lecture is to establish a common structure underlying hypothesis testing and confidence intervals. This structure is found in tests with variance known, variance unknown, sample proportions, and two means.
Can Bob reach Jim? Can Jim reach Bob?
Student's t distribution corrects for the problem that we do not know the population variance of X. We use the sample variance of X and refer to the inferred standard deviation of the mean as the standard error of the mean.
Recall our standard setup to prepare for a "t test" discussion:
How to conduct a "t test":
We concluded with a first pass at applying this structure to the "two means" setting.
