/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 38 Mortality rates vary from city t... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Mortality rates vary from city to city in the United States. We have lots of data on many U.S. cities. Statistical software makes it easy to perform dozens of significance tests on dozens of variables to see which ones best predict mortality rate. One interesting finding is that those cities with major league ballparks tend to have significantly higher mortality rates than other cities. To improve your chances of a long life, should you use this "significant" variable to decide where to live? Explain your answer.

Short Answer

Expert verified
No, don't base residency decisions solely on ballparks and mortality rates.

Step by step solution

01

Understand the Scenario

We are looking into how statistical analysis shows that cities with major league ballparks have higher mortality rates. This raises the question of whether you should avoid living in such cities to potentially live longer.
02

Interpret Significance

Statistical significance suggests that there is a relationship between two variables, in this case, the presence of major league ballparks and higher mortality rates. However, significance does not imply causation.
03

Consider Causation vs. Correlation

Simply because a statistical analysis finds a significant relationship between two variables does not mean one causes the other. There may be other factors influencing both the presence of major league ballparks and mortality rates.
04

Evaluate Other Influencing Factors

Consider other possible factors that could influence mortality rates in large cities, such as population density, traffic pollution, healthcare access, or socioeconomic factors. These factors might contribute more to mortality rates than the presence of ballparks.
05

Conclusion and Decision Making

Given the complexity of the factors involved and the lack of evidence that ballparks cause increased mortality rates, it would be unreasonable to decide where to live based solely on this variable.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Significance Testing
Significance testing is a statistical method used to determine if there is a meaningful relationship between two variables. In the context of the exercise, significance testing was used to explore the relationship between having a major league ballpark in a city and the city’s mortality rates. The core idea behind significance testing is to assess whether any observed patterns in the data could have occurred by chance.

The outcome of a significance test is often represented by a "p-value." This p-value helps us decide if our findings are statistically significant or not. Typically, a p-value of less than 0.05 indicates that the result is statistically significant. However, it's crucial to remember that statistical significance does not imply importance or practical significance. It merely suggests that the observed relationship is unlikely to have happened by chance.
  • Use significance tests cautiously. They reveal potential relationships but not causal links.
  • Always look at the bigger picture. Consider the overall context of the variables.
Correlation vs Causation
Understanding the difference between correlation and causation is essential. Correlation means that two variables have a statistical relationship. For example, the exercise highlighted a correlation between major league ballparks and higher mortality rates.

However, causation means that one variable directly affects another. Just because two variables are correlated does not mean that one causes the other. In the exercise scenario, simply having a major league ballpark doesn't cause higher mortality rates. Other unaccounted factors might be at play.
  • Avoid assuming causation from correlation without further evidence.
  • Investigate other potential influences that might explain the correlation.
Mortality Rates
Mortality rates refer to the number of deaths occurring in a specific population. In statistical studies like the one in the exercise, researchers look at mortality rates to glean insights about the health and environment of a population.

Factors affecting mortality rates are numerous and varied. They include but are not limited to:
  • Healthcare access
  • Socioeconomic status
  • Environmental factors
  • Lifestyle choices
When interpreting findings related to mortality rates, it is vital to consider these multifaceted influences rather than isolating a single variable such as the presence of ballparks.
Data Interpretation
Data interpretation involves making sense of data and its implications. In statistical analysis, particularly in the context of mortality rates, it requires a comprehensive understanding of the data presented and the relationships inferred.

In the ballpark exercise, it’s crucial to question potential biases in data collection and consider the robustness of analysis methods. Additionally, asking questions like "What are the possible confounding factors?" helps avoid misleading conclusions.
  • Examine the data source and methodology used for gathering data.
  • Consider all possible influences and confounders before making inferences.
Effective data interpretation always involves a balanced view, scrutinizing the immediate results while integrating broader context and knowledge from other studies.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A researcher looking for evidence of extrasensory perception (ESP) tests 1000 subjects. Nine of these subjects do significantly better \((P<0.01)\) than random guessing. (a) Nine seems like a lot of people, but you can't conclude that these nine people have ESP. Why not? (b) What should the researcher now do to test whether any of these nine subjects have ESP?

You have data on an SRS of freshmen from your college that shows how long each student spends studying and working on homework. The data contain one high outlier. Will this outlier have a greater effect on a confidence interval for mean completion time if your sample is small or if it is large? Why?

Valium is a common antidepressant and sedative. A study investigated how valium works by comparing its effect on sleep in seven genetically modified mice and eight normal control mice. There was no significant difference between the two groups. The authors say that this lack of significance "is related to the large inter-individual variability that is also reflected in the low power \((20 \%)\) of the test." 12 (a) Explain exactly what power \(20 \%\) against a specific alternative means. (b) Explain in simple language why tests having low power often fail to give evidence against a null hypothesis even when the null hypothesis is really false. (c) What fact about this experiment most likely explains the low power?

You read that a statistical test at the \(\alpha=0.05\) level has probability \(0.49\) of making a Type II error when a specific alternative is true. What is the power of the test against this alternative?

The 2013 Youth Risk Behavior Survey found that 349 individuals in its random sample of 1367 Ohio high school students said that they had texted or emailed while driving in the previous 30 days. That's \(25.5 \%\) of the sample. Why is this estimate likely to be biased? Do you think it is biased high or low? Does the margin of error of a \(95 \%\) confidence interval for the proportion of all Ohio high school students who texted or emailed while driving in the previous 30 days allows for this bias?

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.