Unformatted text preview: uch Better 75 541 Somewhat Better 71 498 About the Same 96 779 Somewhat Worse 50 282 Much Worse 19 65 Total 311 2165 The two‐way table shows the relationship between two categorical variables. The explanatory variable is the patients’ country, Canada or the United States. The response variable is the quality of life a year after the heart attack, with 5 categories. It is hard to compare the counts because the U.S. sample is much larger. Here are the percents of each sample in each outcome: 1 M316 Chapter 23 Dr. Berg Quality of Life Canada United States Much Better 24% 25% Somewhat Better 23% 23% About the Same 31% 36% Somewhat Worse 16% 13% Much Worse 6% 3% Total 100% 100% These are the conditional distributions of the outcomes given the patients’ nationality. The differences are not large, but slightly higher percents of Canadians thought their quality of life was worse. We want to know if there is a significant difference in the two distributions of outcomes. Here is a comparison of the two distributions. Exercise (23.2) Attitudes Toward Recycled Products Recycling is supposed to save resources. Some people think recycled products are lower in quality than other products, a fact that makes recycling less practical. Here are data on attitudes toward coffee filters made of recycled paper. Quality Is: Higher The Same Lower Buyers 20 7 9 Non‐buyers 29 25 43 a) It appears that people who have bought the recycled filters have more positive opinions than those who have not. Give percents to back up this claim. Make a bar graph that compares your percents for buyers and non‐buye...
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This note was uploaded on 09/02/2010 for the course BIO 325 taught by Professor Saxena during the Spring '08 term at University of Texas.
- Spring '08