question 20

Use the value of the linear correlation coefficient to calculate the coefficient of determination. What does this tell you about the explained variation of the data about the regression line? About the unexplained variation?

r=0.199

Calculate the coefficient of determination.

______

(Round to three decimal places as needed.)

question 21

The table shows the numbers of new-vehicle sales (in thousands) in the United States for Company A and Company B for 10 years. The equation of the regression line is

y=0.986x+1,226.47.

Complete parts (a) and (b) below.

New-vehicle sales (CompanyA),x	4,155	3,881	3,560	3,438	3,283	3,098	2,839	2,488	1,953	2,097
New-vehicle sales (CompanyB),y	4,907	4,848	4,829	4,710	4,643	4,456	4,688	3,823	2,933	2,793

(a) Find the coefficient of determination and interpret the result.

r2=

(Round to three decimal places as needed.)

question 22

Save

The number of initial public offerings of stock issued in a 10-year period and the total proceeds of these offerings (in millions) are shown in the table. Construct and interpret a 95% prediction interval for the proceeds when the number of issues is

606.

The equation of the regression line is

y=32.312x+17,947.859.

Issues, x	413	453	677	480	494	394	53	62	178	158
Proceeds, y	19,100	28,455	44,886	30,682	35,994	35,371	21,137	11,664	30,953	29,868

Construct and interpret a 95% prediction interval for the proceeds when the number of issues is

606.

Select the correct choice below and fill in the answer boxes to complete your choice.(Round to the nearest million dollars as needed. Type your answer in standard form where "3.12 million" means 3,120,000.)

A.

There is a 95% chance that the predicted proceeds given

606

issues is between

$___

and

$____

B.

We can be 95% confident that when there are

606

issues, the proceeds will be between

$____ and

$____

question 23

The money raised and spent (both in millions of dollars) by all congressional campaigns for 8 recent 2-year periods are shown in the table. The equation of the regression line is

y=0.956x+16.861.

Find the coefficient of determination and interpret the result.

Money raised, x	457.3	652.7	743.6	791.6	789.9	1028.4	974.6	1200.2
Money spent, y	436.8	692.9	735.6	756.6	745.8	1010.7	937.5	1168.1

Find the coefficient of determination and interpret the result.

r2=

(Round to three decimal places as needed.)

question 24

The equation used to predict college GPA (range 0-4.0) is

y=0.21+0.51x1+0.002x2, where

x1 is high school GPA (range 0-4.0) and

x2 is college board score (range 200-800). Use the multiple regression equation to predict college GPA for a high school GPA of 3.1 and a college board score of 600.

The predicted college GPA for a high school GPA of

3.1 and a college board score of 600 is ___.

(Round to the nearest tenth as needed.)

question 25

The equation used to predict the total body weight (in pounds) of a female athlete at a certain school is

y=120+3.29x1+1.08x2,

where x1

is the female athlete's height (in inches) and x2

is the female athlete's percent body fat, measured as x2%.

Use the multiple regression equation to predict the total body weight for a female athlete who is

68 inches tall and has 30% body fat.

The predicted total body weight for a female athlete who is

68

inches tall and has

30%

body fat is ____

pounds. (Round to the nearest tenth as needed.)