Page 53 - Statistics II for Dummies

Chapter 3

Reviewing Confidence Intervals

and Hypothesis Tests

In This Chapter
▶ Utilizing confidence intervals to estimate parameters
▶ Testing models by using hypothesis tests
▶ Finding the probability of getting it right and getting it wrong
▶ Discovering power in a large sample size

ne of the major goals in statistics is to use the information you collect
Ofrom a sample to get a better idea of what’s going on in the entire
population you’re studying (because populations are generally large and
exact info is often unknown). Unknown values that summarize the population
are called population parameters. Researchers typically want to either get
a handle on what those parameters are or test a hypothesis about the
population parameters.

In Stats I, you probably went over confidence intervals and hypothesis tests
for one and two population means and one and two population proportions.
Your instructor hopefully emphasized that no matter which parameters
you’re trying to estimate or test, the general process is the same. If not, don’t
worry; this chapter drives that point home.
This chapter reviews the basic concepts of confidence intervals and
hypothesis tests, including the probabilities of making errors by chance. I
also discuss how statisticians measure the ability of a statistical procedure
to do a good job — of detecting a real difference in the populations, for
example.

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