Quality Control: When new equipment is used to manufacture aircraft altimeters, the new altimeters are better because the variation in the errors is reduced so that the readings are more consistent. Examples of Hypotheses that can be TestedĪircraft Safety: The Federal Aviation Administration claims that the mean weight of an airline passenger (including carry-on baggage) is greater than 185 lb, which it was 20 years ago. Medicine: Medical researchers claim that when people with colds are treated with echinacea, the treatment has no effect. Business: A newspaper headline makes the claim that most workers get their jobs through networking. Genetics: The Genetics & IVF Institute claims that its XSORT method allows couples to increase the probability of having a baby girl. The main objective of this chapter is to develop the ability to conduct hypothesis tests for claims made about a population proportion p, a population mean , or a population standard deviation . A hypothesis test (or test of significance) is a standard procedure for testing a claim about a property of a population. In statistics, a hypothesis is a claim or statement about a property of a population. In Chapter 7 we presented methods for estimating a population parameter with a confidence interval, and in this chapter we present the method of hypothesis testing.

The two main activities of inferential statistics are using sample data to (1) estimate a population parameter (such as estimating a population parameter with a confidence interval), and (2) test a hypothesis or claim about a population parameter.

Methods of inferential statistics use sample data to make an inference or conclusion about a population. In Chapters 2 and 3 we used “descriptive statistics” when we summarized data using tools such as graphs, and statistics such as the mean and standard deviation. Chapter 8Hypothesis Testing 8-1 Review and Preview 8-2 Basics of Hypothesis Testing 8-3 Testing a Claim about a Proportion 8-4 Testing a Claim About a Mean: σKnown 8-5 Testing a Claim About a Mean: σNotKnown 8-6 Testing a Claim About a Standard Deviation or Variance

Xsort method of gender selection