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Introduction to Statistics II - Lecture 10

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Lecture 10 - Hypothesis Testing - Two Means, Two Proportions, Paired Data

Studies often compare two groups. For example, researchers are interested in the effect aspirin has in preventing heart attacks. Over the last few years, newspapers and magazines have reported about various aspirin studies involving two groups. Typically, one group is given aspirin and the other group is given a placebo. Then, the heart attack rate is studied over several years.

There are other situations that deal with the comparison of two groups. For example, studies compare various diet and exercise programs. Politicians compare the proportion of individuals from different income brackets who might vote for them. Students who are interested in whether SAT or GRE preparatory courses really help raise their scores.

In the previous lecture, you learned to conduct hypothesis tests on single means and single proportions. This lecture expands upon that and will compare two averages or two proportions to each other. The procedure is still the same, just expanded.

Dr. Barbara Illowsky, Susan Dean
Collaborative Statistics
Date accessed: 2009-01-17
License: Creative Commons Attribution 2.0

Lecture Material

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