9: Hypothesis Tests and Confidence Intervals for Two Populations
- Page ID
- 24059
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There are many instances where researchers wish to compare two groups. A clinical trial may want to use a control group and an experiment group to see if a new medication is effective. Identical twin studies help geneticists learn more about inherited traits. Educators may want to test to see if there is a difference between before and after test scores. A farmer may wish to see if there is a difference between two types of fertilizer. A marketing firm may want to see if there is a preference between two different bottle designs. Hypothesis testing for two groups takes on similar steps as one group. It is important to know if the two groups are dependent (related) or independent (not related) from one another.
- 9.2: Two Independent Groups
- This section will look at how to analyze a difference in the mean for two independent samples. As with all other hypothesis tests and confidence intervals, the process is the same, though the formulas and assumptions are different.