Exam 5: Two-Way Tables

The U.S. Food and Drug Administration (FDA) ruled that the emergency contraception "morning after" pill (Plan B) must now be available over the counter. Following that ruling, SurveyUSA polled a random sample of 500 Los Angeles adults, asking them if they agree with the FDA's decision. Here are the results broken down by gender: ​ ​ Male Female All Agree 112 94 206 Disagree 119 148 267 Not sure 17 10 27 What percent of those who agree with the ruling are male?

A study in Sweden looked at former elite soccer players; people who had played soccer, but not at the elite level; and people of the same age who did not play soccer. Here is a two-way table that classifies these subjects based on whether they had arthritis of the hip or knee by their mid-fifties: ? ? Elite Non-elite Did not play Arthritis 10 9 24 No arthritis 61 206 548 How many people do these data describe?

The U.S. Food and Drug Administration (FDA) ruled that the emergency contraception "morning after" pill (Plan B) must now be available over the counter. Following that ruling, SurveyUSA polled a random sample of 500 Los Angeles adults, asking them if they agree with the FDA's decision. Here are the results broken down by gender: ? ? Male Female All Agree 112 94 206 Disagree 119 148 267 Not sure 17 10 27 What might we conclude about Los Angeles in the spring of 2013?

X and Y are two categorical variables. What is the best way to determine whether there is an association between them?

The U.S. Food and Drug Administration (FDA) ruled that the emergency contraception "morning after" pill (Plan B) must now be available over the counter. Following that ruling, SurveyUSA polled a random sample of 500 Los Angeles adults, asking them if they agree with the FDA's decision. Here are the results broken down by gender: ​ ​ Male Female All Agree 112 94 206 Disagree 119 148 267 Not sure 17 10 27 What percent of those polled agree with the ruling?

A study in Sweden looked at former elite soccer players; people who had played soccer, but not at the elite level; and people of the same age who did not play soccer. Here is a two-way table that classifies these subjects based on whether they had arthritis of the hip or knee by their mid-fifties: ? ? Elite Non-elite Did not play Arthritis 10 9 24 No arthritis 61 206 548 What proportion of the people in this study had arthritis of the hip or knee?

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells from patients with CFS, researchers identified DNA from a human gamma-retrovirus (XMRV) in 68 of 101 patients, compared with 8 of 218 healthy controls. What percent of the healthy controls were found to have XMRV DNA?

A study in Sweden looked at former elite soccer players; people who had played soccer, but not at the elite level; and people of the same age who did not play soccer. Here is a two-way table that classifies these subjects based on whether they had arthritis of the hip or knee by their mid-fifties: ? ? Elite Non-elite Did not play Arthritis 10 9 24 No arthritis 61 206 548 Based on this study, what can you conclude about playing elite soccer?

Obesity is a growing public health concern worldwide. Adults with a body mass index (BMI) of 25 or above are considered overweight or obese. The table below shows the number of adults (in millions) who are overweight or obese in countries with different income levels, based on data from the World Health Organization and the United Nation. ​ ​ Income level BMI \geq BMI < Total High 549 414 963 Upper middle 612 1042 1654 Lower middle 288 1083 1371 Low 63 357 420 All 1512 2896 4408 ​ -What percent of adults worldwide are overweight or obese? ​

The conditional distribution of prostate cancer mortality, given a man's race, shows that black men and white men were, overall, about equally likely to die from prostate cancer. However, when we look at the study broken down by age groups older than and younger than 65, we find that in each age group, black men were more than twice as likely to die from prostate cancer than white men. This apparent contradiction is an example of

A survey was designed to study how brook trout populations respond to various levels of urbanization. Urbanization had three levels: low, medium, and high impact. Historical habitats for brook trout were observed, with 200 habitats randomly selected within each level of urbanization, for a total of 600 habitats. Researchers marked each population as extirpated or present. The data are given in the following two-way table. ? ? Extirpated Present Total Low impact 25 175 200 Medium impact 80 120 200 High impact 195 5 200 What percent of all historical brook trout populations were found to be extirpated in the sample?

Obesity is a growing public health concern worldwide. Adults with a body mass index (BMI) of 25 or above are considered overweight or obese. The table below shows the number of adults (in millions) who are overweight or obese in countries with different income levels, based on data from the World Health Organization and the United Nation. ​ ​ Income level BMI \geq BMI < Total High 549 414 963 Upper middle 612 1042 1654 Lower middle 288 1083 1371 Low 63 357 420 All 1512 2896 4408 ​ -More than three-fourths of adults who are overweight or obese live in high-income or upper-middle-income countries.

Obesity is a growing public health concern worldwide. Adults with a body mass index (BMI) of 25 or above are considered overweight or obese. The table below shows the number of adults (in millions) who are overweight or obese in countries with different income levels, based on data from the World Health Organization and the United Nation. ​ ​ Income level BMI \geq BMI < Total High 549 414 963 Upper middle 612 1042 1654 Lower middle 288 1083 1371 Low 63 357 420 All 1512 2896 4408 ​ -What percentage of adults in high-income countries are overweight or obese? ​

Hybrid cars and SUVs are about twice as likely to kill pedestrians as their gas/diesel counterparts are. These deaths may not have been due to how silent hybrids are. A careful study of more than 200,000 traffic-related fatalities shows that most fatalities occurred when the hybrids were going faster than 35 mph-when they were making the same amount of noise as a conventional vehicle. The difference in fatality rates could be due to market distribution differences: Hybrids could be more common in crowded areas with high levels of pedestrian traffic, which in turn could lead to a higher chance of pedestrian accidents. Which of the following statements is NOT true?

Chronic fatigue syndrome (CFS) is a debilitating disease of unknown etiology that is estimated to affect 17 million people worldwide. Studying peripheral blood mononuclear cells from patients with CFS, researchers identified DNA from a human gamma-retrovirus (XMRV) in 68 of 101 patients, compared with 8 of 218 healthy controls. Which of the following two-way tables represents the study findings correctly?

A study prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6294 men and women participating in the Sleep Heart Health Study. Study participants were classified into four groups depending on the extent of their sleep-disordered breathing (none, mild, moderate, or severe). The counts of deaths over the course of the study are reported for each group in the following two-way table: sleep-disordered breathing none mild moderate severe total death 476 320 165 86 1047 no death 2953 1477 562 255 5247 total 3429 1797 727 341 What is the proportion of subjects with no sleep-disordered breathing who died of any cause during the study?

The U.S. Food and Drug Administration (FDA) ruled that the emergency contraception "morning after" pill (Plan B) must now be available over the counter. Following that ruling, SurveyUSA polled a random sample of 500 Los Angeles adults, asking them if they agree with the FDA's decision. Here are the results broken down by gender: ​ ​ Male Female All Agree 112 94 206 Disagree 119 148 267 Not sure 17 10 27 What percent of males agree with the ruling?

Obesity is a growing public health concern worldwide. Adults with a body mass index (BMI) of 25 or above are considered overweight or obese. The table below shows the number of adults (in millions) who are overweight or obese in countries with different income levels, based on data from the World Health Organization and the United Nation. ​ ​ Income level BMI \geq BMI < Total High 549 414 963 Upper middle 612 1042 1654 Lower middle 288 1083 1371 Low 63 357 420 All 1512 2896 4408 ​ -We can conclude from these data that having a high income causes adults to be overweight or obese.

Which of the following graphs would display a conditional distribution?

The following graph describes the percent of American adults aged 20 and older who used antidepressants in 2010, based on the 2010 America's State of Mind report. ​ ​ In 2010, approximately 63% of women older than age 20 years used antidepressants.