Interpreting the Coefficient of Determination. In Exercises 5–8, use the value of the linear correlation coefficient r to find the coefficient of determination and the percentage of the total variation that can be explained by the linear relationship between the two variables.

Bears r = 0.783 (x = head width of a bear, y = weight of a bear)

Short Answer

Expert verified

The coefficient of determination is 0.613.

Here, 61.3% of the variation is explained by the linear association between the head width and the weight of a bear.

And 38.7% variation in the weight of a bear is explained by other factors and random variation.

Step by step solution

01

Given information

The linear correlation coefficient between the head width and the weight of a bear is 0.783.

02

Coefficient of determination

The square of the linear correlation coefficient between the two variables equals the coefficient of determination.

Here, the linear correlation coefficient (r) between the head width and the weight of a bear equals0.783.

Thus,

\(\begin{array}{c}{\rm{Coefficient}}\;{\rm{of}}\;{\rm{determination}} = {r^2}\\ = {0.783^2}\\ = 0.613\end{array}\)

Therefore, the value of the coefficient of determination is 0.613.

03

Percentage of variation

Here,

\(\begin{array}{c}{r^2} = 0.613\\ = \frac{{61.3}}{{100}} \times 100\% \\ = 61.3\% \end{array}\)

Therefore, the percentage of the variation explained by the linear association between the head width and the weight of a bear is 61.3%.

The rest \(100\% - 61.3\% = 38.7\% \) variation is explained by other factors and random variation.

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

The following exercises are based on the following sample data consisting of numbers of enrolled students (in thousands) and numbers of burglaries for randomly selected large colleges in a recent year (based on data from the New York Times).

Conclusion The linear correlation coefficient r is found to be 0.499, the P-value is 0.393, and the critical values for a 0.05 significance level are\( \pm 0.878\). What should you conclude?

In Exercises 9 and 10, use the given data to find the equation of the regression line. Examine the scatterplot and identify a characteristic of the data that is ignored by the regression line.

Explore! Exercises 9 and 10 provide two data sets from “Graphs in Statistical Analysis,” by F. J. Anscombe, the American Statistician, Vol. 27. For each exercise,

a. Construct a scatterplot.

b. Find the value of the linear correlation coefficient r, then determine whether there is sufficient evidence to support the claim of a linear correlation between the two variables.

c. Identify the feature of the data that would be missed if part (b) was completed without constructing the scatterplot.

x

10

8

13

9

11

14

6

4

12

7

5

y

9.14

8.14

8.74

8.77

9.26

8.10

6.13

3.10

9.13

7.26

4.74

let the predictor variable x be the first variable given. Use the given data to find the regression equation and the best predicted value of the response variable. Be sure to follow the prediction procedure summarized in Figure 10-5 on page 493. Use a 0.05 significance level.

Head widths (in.) and weights (lb) were measured for 20 randomly selected bears (from Data Set 9 “Bear Measurements” in Appendix B). The 20 pairs of measurements yield\(\bar x = 6.9\)in.,\(\bar y = 214.3\)lb, r= 0.879, P-value = 0.000, and\(\hat y = - 212 + 61.9x\). Find the best predicted value of\(\hat y\)(weight) given a bear with a head width of 6.5 in.

Finding a Prediction Interval. In Exercises 13–16, use the paired data consisting of registered Florida boats (tens of thousands) and manatee fatalities from boat encounters listed in Data Set 10 “Manatee Deaths” in Appendix B. Let x represent number of registered boats and let y represent the corresponding number of manatee deaths. Use the given number of registered boats and the given confidence level to construct a prediction interval estimate of manatee deaths.

Boats Use x = 85 (for 850,000 registered boats) with a 99% confidence level.

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