Chapter 4: Q.4.4. Linear Correlation (page 191)

The coefficient of determination of a set of data points is 0.716.

a. Can you determine the linear correlation coefficient? If yes, obtain it. If no, why not?

b. Can you determine whether the slope of the regression line is positive or negative? Why or why not?

c. If we tell you that the slope of the regression line is negative, can you determine the linear correlation coefficient? If yes, obtain it. If no, why not?

d. If we tell you that the slope of the regression line is positive, can you determine the linear correlation coefficient? If yes, obtain it. If no, why not?

Short Answer

Expert verified

(a) We are not supposed to determine the linear correlation coefficient reven though we have the value of the coefficient of determination r2

(b) We are not required to identify the sign of the slope of the regression line even though we have the value of the coefficient of determination (r2)

(c) It is impossible to calculate the linear correlation coefficient.

(d) It is impossible to calculate the linear correlation coefficient.

Step by step solution

01

Part (a)Step 1: Given information

Given in the question that, The coefficient of determination of a set of data points is0.716 . We need to determine the linear correlation coefficient

02

Part(a) Step 2: Explanation

A set of data points has a coefficient of determination of 0.716.

The coefficient of determination for a set of data points isr2=0.716in this case.

We are not supposed to determine the linear correlation coefficient (r)even though we have the value of the coefficient of determination r2because the coefficient of determination cannot tell us whether there is a linear relationship between the supplied variables.

03

Part(b) Step 1: Given information

Given in the question that, The coefficient of determination of a set of data points is 0.716. We need to determine that whether the slope of the regression line is positive or negative

04

Part (b) Step 2: Explanation

A set of data points has a coefficient of determination of 0.716.

We are not required to identify the sign of the slope of the regression line even though we have the value of the coefficient of determination r2because r=±r2.

05

Part(c) Step 1: Given information

Given in the question that, The coefficient of determination of a set of data points is 0.716. We need to determine the linear correlation coefficient if the slope of the regression line is negative.

06

Part(c) Step 2: Explanation

A set of data points has a coefficient of determination of 0.716.

We don't know if there is a linear relationship between the variables because the coefficient of determination is negative and the slope sign is negative. As a result, it is impossible to calculate the linear correlation coefficient.

07

Part(d) Step 1: Given information

Given in the question that, The coefficient of determination of a set of data points is 0.716. We need to determine the linear correlation coefficient if the slope of the regression line is positive.

08

Part(d) Step 2: Explanation

A set of data points has a coefficient of determination of 0.716.

Even though the coefficient of determination is positive and the slope is positive, we are unsure if there is a linear relationship between the variables. As a result, it is impossible to calculate the linear correlation coefficient.

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 Vaia!

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

Acreage and Value. The document Arizona Residential Property Valuation System, published by the Arizona Department of Revenue, describes how county assessors use computerized systems to value single-family residential properties for property tax purposes. On the Weiss Stats site are data on lot size (in acres) and assessed value (in thousands of dollars) for a sample of homes in a particular area.

a. Obtain a scatterplot for the data.

b. Decide whether finding a regression line for the data is reasonable. If so, then also do parts (c) - f).

A value of rclose to ------- indicates that there is either no linear relationship between the variables or a weak one.

More Money, More Beer?Does a higher state per capita income equate to a higher per capita beer consumption? From the document Survey of Current Business, published by the U.S. Bureau of Economic Analysis, and from the Brewer's Almanac, published by the Beer Institute, we obtained data on personal income per capita, in thousands of dollars, and per capita beer consumption, in gallons, for the 50states and Washington. D.C. Those data are provided on the Weiss Stats site.

a. Obtain a scatterplot for the data.

b. Decide whether finding a regression line for the data is reasonable. If so, then also do parts (c)-(f).

4.85 A measure of the amount of variation in the observed values of the response variable explained by the regression is the-----. The mathematical abbreviation for it is----.

In Exercise 4.5, we give linear equations. For each equation,

a. find the y-intercept and slope.

b. determine whether the line slopes upward, slopes downward, or is horizontal, without graphing the equation.

c. use two points to graph the equation.

Given equation is,

y=4x+3

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.

Sign-up for free