When you have completed this chapter, you will be able to: Explain the the difference between dependent and independent samples, conduct a test of hypothesis and obtain a confidence interval estimate for the difference between two population means using independent samples and using matched pair sample. | Two-Sample Tests of Hypothesis Chapter 11 GOALS Conduct a test of a hypothesis about the difference between two independent population means. Conduct a test of a hypothesis about the difference between two population proportions. Conduct a test of a hypothesis about the mean difference between paired or dependent observations. Understand the difference between dependent and independent samples. Comparing two populations – Some Examples Is there a difference in the mean value of residential real estate sold by male agents and female agents in south Florida? Is there a difference in the mean number of defects produced on the day and the afternoon shifts at Kimble Products? Is there a difference in the mean number of days absent between young workers (under 21 years of age) and older workers (more than 60 years of age) in the fast-food industry? Is there is a difference in the proportion of Ohio State University graduates and University of Cincinnati graduates who pass the state | Two-Sample Tests of Hypothesis Chapter 11 GOALS Conduct a test of a hypothesis about the difference between two independent population means. Conduct a test of a hypothesis about the difference between two population proportions. Conduct a test of a hypothesis about the mean difference between paired or dependent observations. Understand the difference between dependent and independent samples. Comparing two populations – Some Examples Is there a difference in the mean value of residential real estate sold by male agents and female agents in south Florida? Is there a difference in the mean number of defects produced on the day and the afternoon shifts at Kimble Products? Is there a difference in the mean number of days absent between young workers (under 21 years of age) and older workers (more than 60 years of age) in the fast-food industry? Is there is a difference in the proportion of Ohio State University graduates and University of Cincinnati graduates who pass the state Certified Public Accountant Examination on their first attempt? Is there an increase in the production rate if music is piped into the production area? Comparing Two Population Means No assumptions about the shape of the populations are required. The samples are from independent populations. The formula for computing the test statistic (z) is: EXAMPLE The U-Scan facility was recently installed at the Byrne Road Food-Town location. The store manager would like to know if the mean checkout time using the standard checkout method is longer than using the U-Scan. She gathered the following sample information. The time is measured from when the customer enters the line until their bags are in the cart. Hence the time includes both waiting in line and checking out. Step 1: State the null and alternate hypotheses. (keyword: “longer than”) H0: µS ≤ µU H1: µS > µU Step 2: Select the level of significance. The .01 significance level is stated in the problem. Example 1 continued Step 3: .
