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91Ó°ÊÓ

If women always married men who were 2 years older than themselves, what would the correlation between the ages of husband and wife be? (a) 2 (b) 1 (c) 0.5 (d) 0 (e) Can't tell without seeing the data

Short Answer

Expert verified
The correlation is 1, corresponding to option (b).

Step by step solution

01

Understanding Correlation

Correlation is a statistical measure that describes the extent to which two variables are linearly related. A correlation of 1 indicates a perfect positive linear relationship, 0 indicates no linear relationship, and -1 indicates a perfect negative linear relationship.
02

Defining the Relationship

In the given exercise, every wife marries a husband who is exactly 2 years older than herself. This implies a perfect linear relationship between their ages.
03

Calculating the Correlation Coefficient

Since the ages are perfectly linearly related with each husband being exactly 2 years older, the correlation coefficient is 1. This is because a perfect linear relationship exists, where the difference is constant.
04

Selecting the Correct Answer

Based on the steps above, the correlation between the ages is 1, which corresponds to option (b).

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Key Concepts

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

Linear Relationship
A linear relationship is a connection between two variables that can be represented by a straight line on a graph. In such relationships, any change in one variable will result in a proportional change in the other. This relationship is characterized by a constant rate of change, which means if you increase one variable, the other will increase or decrease at a constant fixed rate.

In the context of age difference between husbands and wives, a linear relationship is established when there's a consistent age gap, such as a husband always being 2 years older than his wife. Here, each pair of ages corresponds to a point on the line, reflecting a direct and stable relationship. This is an example of a perfect linear relationship, as depicted in the problem.
Correlation Coefficient
The correlation coefficient is a numerical measure that evaluates the degree of the relationship between two variables. It is denoted by the symbol \( r \) and ranges from -1 to 1.

Here’s what the values mean:
  • A correlation coefficient of 1 indicates a perfect positive correlation, meaning both variables move in the same direction at the same rate.
  • A correlation coefficient of -1 indicates a perfect negative correlation, meaning one variable increases while the other decreases proportionally.
  • A correlation coefficient of 0 means there is no linear relationship between the variables.
In cases where women marry men who are consistently 2 years older, the correlation would be 1, illustrating a perfect linear relationship between the variables.
Statistical Measure
A statistical measure is a tool used in statistics to summarize or describe a set of data with a single entity. Correlation is one such measure that helps us understand how two variables interact with each other.

It captures the essence of their linear relationship and gives us a quantifiable way to describe how closely these two variables are related. Understanding correlation as a statistical measure helps in predicting and making inferences about one variable when we know the other.

In the scenario of ages among married couples, the statistical measure shows that because there's a consistent age gap, the correlation is maximized, indicating a strong relationship.
Age Relationship
The age relationship in couples can be analyzed to understand mutual patterns. For example, when one partner is always consistently older or younger by a specific number of years, this age relationship can illustrate unique societal behaviors or choices.

In the exercise mentioned, if every marriage shows a pattern where the husband is two years older than his wife, the age relationship forms a predictable pattern. This kind of pattern points towards possibly chosen societal norms or minimized variability due to fixed expectations, easily described by a correlation coefficient. Therefore, age relationship helps in better understanding of social dynamics and expectation norms.

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Most popular questions from this chapter

Measurements on young children in Mumbai, India, found this least-squares line for predicting height \(y\) from \(\operatorname{arm} \operatorname{span} x:\) $$\hat{y}=6.4+0.93 x$$ Measurements are in centimeters \((\mathrm{cm})\). By looking at the equation of the least-squares regression line, you can see that the correlation between height and arm span is (a) greater than zero. (b) less than zero. (c) 0.93 . (d) 6.4 . (e) Can't tell without seeing the data.

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