/*! 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 7 What is the relationship between... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

What is the relationship between the sign of the correlation coefficient and the sign of the slope of the regression line?

Short Answer

Expert verified
The sign of the correlation coefficient matches the sign of the slope of the regression line.

Step by step solution

01

Understand Correlation Coefficient

The correlation coefficient, denoted as \( r \), is a measure that indicates the extent to which two variables are linearly related. Its value ranges from -1 to 1, where values closer to 1 indicate a strong positive linear relationship, values closer to -1 indicate a strong negative linear relationship, and values around 0 indicate no linear relationship.
02

Understand Regression Line Slope

The slope of a regression line, denoted as \( m \), describes how much the dependent variable (y) changes for a unit change in the independent variable (x). A positive slope indicates that as \( x \) increases, \( y \) tends to increase, whereas a negative slope indicates that as \( x \) increases, \( y \) tends to decrease.
03

Relationship Between \( r \) and \( m \)

There is a direct relationship between the sign of the correlation coefficient \( r \) and the sign of the slope \( m \) of the regression line. If \( r \) is positive, the slope \( m \) will also be positive, indicating a positive linear relationship. If \( r \) is negative, the slope \( m \) will be negative, indicating a negative linear relationship. This is because the regression line is a way to model the linear relationship measured by \( r \).

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.

Regression Line Slope
The slope of a regression line is a key concept in understanding relationships between variables in a data set. It's represented as \( m \) in the equation of a straight line: \( y = mx + b \). Here, \( b \) is the y-intercept. The slope \( m \) tells us how much the dependent variable, \( y \), is expected to change when the independent variable, \( x \), changes by one unit.

When \( m \) is positive, it means that there is a positive relationship between \( x \) and \( y \). In simple terms, as \( x \) increases, \( y \) tends to increase as well. Conversely, a negative slope indicates that as \( x \) increases, \( y \) tends to decrease. For instance, if we're looking at the relationship between hours studied and test scores, a positive slope would suggest higher scores with more study hours, while a negative slope would mean scores decrease with more studying, which could imply over-studying or burnout.
  • Positive Slope: As one variable increases, so does the other.
  • Negative Slope: As one variable increases, the other decreases.
The slope is essential in predictive modeling as it quantifies the strength and direction of the relationship between variables.
Linear Relationship
A linear relationship is a statistical term that describes a straight-line connection between two variables. Such a relationship is characterized by the direct proportionality of changes in one variable to changes in the other.

In a linear relationship, any increase or decrease in one variable leads to a consistent and predictable change in another. This can be visualized on a graph where the plotted points make a straight line. The steeper the line, the stronger the relationship between the two variables.
  • Strong Linear Relationship: Points are close to the line, indicating less variance and a consistent pattern.
  • Weak Linear Relationship: Points are more spread out from the line, suggesting more variance and a less predictable pattern.
Understanding the linear relationship helps in predicting outcomes and identifying trends. It's pivotal in various fields like economics, psychology, and environmental studies, where data trends over time or under different conditions are analyzed.
Statistical Analysis
Statistical analysis involves collecting, examining, and interpreting data to uncover patterns and trends. It's a tool used extensively in research and business to make data-driven decisions.

There are many methods of statistical analysis, but in the context of correlation coefficient and regression, linear regression is a significant method. It aims to predict the value of a dependent variable based on the independent variable's value, assuming a linear relationship between the two.
  • Descriptive Statistics: Includes mean, median, and mode, providing a summary of the data.
  • Inferential Statistics: Uses sampled data to make inferences or predictions about a population.
  • Correlational Analysis: Measures how variables are related.
  • Linear Regression: A method to model and analyze the linear relationship between two variables.
Understanding these concepts allows researchers to develop accurate models, test hypotheses, and draw conclusive insights. It's crucial for any statistical inquiry, leading to informed decisions based on data.

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

Compute \(r\) for the data set shown. Explain the reason for the value of \(r\). Interchange the values of \(x\) and \(y .\) Compute \(r\) for this data set. Explain the results of the comparison. $$ \begin{array}{l|llllll} x & 1 & 2 & 3 & 4 & 5 \\ \hline y & 4 & 7 & 10 & 13 & 16 \end{array} $$

Use the same data as for the corresponding exercises in Section \(10-1 .\) For each exercise, find the equation of the regression line and find the \(y^{\prime}\) value for the specified \(x\) value. Remember that no regression should be done when \(r\) is not significant. NHL Assists and Total Points The number of assists and the total number of points for a sample of NHL scoring leaders are shown. $$ \begin{array}{l|ccccccc} \text { Assists } & 26 & 29 & 32 & 34 & 36 & 37 & 40 \\ \hline \text { Total points } & 48 & 68 & 66 & 69 & 76 & 67 & 84 \end{array} $$ Find \(y^{\prime}\) when \(x=30\) assists.

A college statistics professor is interested in the relationship among various aspects of students' academic behavior and their final grade in the class. She found a significant relationship between the number of hours spent studying statistics per week, the number of classes attended per semester, the number of assignments turned in during the semester, and the student's final grade. This relationship is described by the multiple regression equation \(y^{\prime}=-14.9+0.93359 x_{1}+\) \(0.99847 x_{2}+5.3844 x_{3} .\) Predict the final grade for a student who studies statistics 8 hours per week \(\left(x_{1}\right)\), attends 34 classes \(\left(x_{2}\right),\) and turns in 11 assignments \(\left(x_{3}\right)\)

Do a complete regression analysis by performing these steps. a. Draw a scatter plot. b. Compute the correlation coefficient. c. State the hypotheses. d. Test the hypotheses at \(\alpha=0.05 .\) Use Table I. e. Determine the regression line equation if \(r\) is significant. \(f\). Plot the regression line on the scatter plot, if appropriate. g. Summarize the results. Coal Production These data were obtained from a sample of counties in southwestern Pennsylvania and indicate the number (in thousands) of tons of bituminous coal produced in each county and the number of employees working in coal production in each county. Predict the amount of coal produced for a county that has 500 employees. $$ \begin{array}{l|llllllll} \text { No. of } & & & & & & & & \\ \text { employees } x & 110 & 731 & 1031 & 20 & 118 & 1162 & 103 & 752 \\ \hline \text { Tons } y & 227 & 5410 & 5328 & 147 & 729 & 8095 & 635 & 6157 \end{array} $$

Do a complete regression analysis by performing these steps. a. Draw a scatter plot. b. Compute the correlation coefficient. c. State the hypotheses. d. Test the hypotheses at \(\alpha=0.05 .\) Use Table I. e. Determine the regression line equation if \(r\) is significant. \(f\). Plot the regression line on the scatter plot, if appropriate. g. Summarize the results. Television Viewers A television executive selects 10 television shows and compares the average number of viewers the show had last year with the average number of viewers this year. The data (in millions) are shown. Describe the relationship. $$ \begin{array}{l|ccccc} \text { Viewers last year } x & 26.6 & 17.85 & 20.3 & 16.8 & 20.8 \\ \hline \text { Viewers this year } y & 28.9 & 19.2 & 26.4 & 13.7 & 20.2 \\ \text { Viewers last year } x & 16.7 & 19.1 & 18.9 & 16.0 & 15.8 \\ \hline \text { Viewers this year } y & 18.8 & 25.0 & 21.0 & 16.8 & 15.3 \end{array} $$

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.