/*! 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 1 Explain why a strong correlation... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Explain why a strong correlation would be found between weekly sales of firewood and weekly sales of cough drops over a 1-year period. Would it imply that fires cause coughs?

Short Answer

Expert verified
The strong correlation is due to seasonal demand from cold weather, not causation between fires and coughs.

Step by step solution

01

Understanding Correlation

Correlation measures the strength and direction of a linear relationship between two variables. A strong correlation indicates that the variables tend to increase or decrease together, but it does not imply causation.
02

Analyzing the Variables

Identify the variables involved: weekly sales of firewood and weekly sales of cough drops. Consider external factors that could affect both, such as the season or weather.
03

Considering External Influences

Think about external factors that could lead to increased sales of both products at the same time. Cold weather could drive both firewood sales (for heating) and cough drop sales (due to an increase in colds and respiratory issues).
04

Determining Causality

Reflect on whether one variable could cause the other. While firewood sales and cough drop sales show strong correlation, they are not directly causing each other. Instead, they are both influenced by seasonal changes.
05

Conclusion

Conclude that the strong correlation is due to a common cause—cold weather—rather than one variable causing the other. Therefore, fires do not cause coughs, but both sales increase concurrently due to seasonal demand.

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.

Causation versus Correlation
Causation and correlation are two distinct concepts in statistics, often misunderstood. Causation implies that one event is the direct result of another, establishing a cause-and-effect relationship. On the other hand, correlation simply indicates that two variables move together in some way, either directly or inversely, without implying direct causality.

For instance, the correlation between weekly sales of firewood and cough drops might be strong, meaning that as one increases, the other does too. However, this doesn't mean the sale of firewood causes an increase in cough drops sales—or vice versa. This relationship could be driven by other factors, which become evident in further analysis.
External Factors in Data Analysis
When analyzing data, it's crucial to consider external factors that may influence the variables in question. These factors can provide insight into the relationship between variables that might otherwise seem directly connected.

In our example of firewood and cough drops, external factors such as weather conditions play a significant role. Cold weather not only motivates people to buy firewood for heating but also increases the likelihood of colds and hence increases the demand for cough drops. By identifying such external influences, we better understand that the correlation isn't a result of direct causation, but rather simultaneous responses to these external conditions.
Seasonal Demand
Seasonal demand refers to fluctuations in the market driven by changes in seasons. Certain products experience higher demand during specific times of the year due to weather or cultural practices.

In the case of firewood and cough drops, these products have higher sales during cold seasons. This is due to a need for heating and an increase in colds, which drive people to buy both firewood and cough drops. Recognizing seasonal demand helps explain why these products show strong correlation in their sales without implying that they directly influence each other.
Correlation Interpretation
Interpreting correlation requires understanding not just the statistical outcome but the context around the data as well. A correlation coefficient ranges from -1 to 1, where values close to 1 or -1 indicate a strong correlation between two variables.

In interpreting our example, a high positive correlation coefficient between firewood sales and cough drops would suggest that they tend to increase together. The correct interpretation goes beyond the number and considers external factors and the lack of direct causation. It explains how these two items might rise together due to a common cause, like colder weather, rather than influencing each other directly.
Statistical Analysis
Statistical analysis involves a range of techniques used to understand and interpret data. It includes identifying trends, testing hypotheses, and establishing relationships between variables, regardless of direct causality.

In the given scenario, statistical analysis would start with observing the correlation between cough drop and firewood sales. Then, it would explore deeper causal relationships and external factors like seasonality. This comprehensive analysis provides a more holistic view, ensuring that the correlation does not misleadingly suggest causation. Careful statiscal analysis prevents wrong conclusions and directs focus on the actual factors driving the observed trends.

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

Construct an example for which correlation between two variables is masked by grouping over a third variable.

It is said that a higher proportion of drivers of red cars are given tickets for traffic violations than the drivers of any other color car. Does this mean that if you drove a red car rather than a white car, you would be more likely to receive a ticket for a traffic violation? Explain.

Lave (1990) discussed studies that had been done to test the usefulness of seat belts before and after their use became mandatory. One possible method of testing the usefulness of mandatory seat belt laws is to measure the number of fatalities in a particular region for the year before and the year after the law went into effect and to compare them. If such a study were to find substantially reduced fatalities during the year after the law went into effect, could it be claimed that the mandatory seat belt law was completely responsible? Explain. (Hint: Consider factors such as weather and the anticipatory effect of the law.)

Suppose a study measured total beer sales and number of highway deaths for 1 month in various cities. Explain why it would make sense to divide both variables by the population of the city before determining whether a relationship exists between them.

t. One of the features that may suggest a cause-and-effect relationship from an observational study is a "dose-response" relationship. a. Explain what is meant by a dose-response relationship. b. Give an example of a possible dose-response relationship. c. Can a dose-response relationship exist if the explanatory variable is categorical (and not ordinal)? Explain.

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.