9.3

1.The table shows the total square footage(in billions) of retailing space at shopping centers and their sales(in billions ofdollars) for 10 years. The equation of the regression line is

y=627.117x2336.688. Complete parts a and b.

Total SquareFootage,

x

5.1

5.2

5.3

5.4

5.6

5.8

5.9

5.8

5.9

6.1

Sales,

y

872.4

944.8

995.9

1056.1

1104.7

1223.5

1292.7

1349.8

1448.1

1526.4

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

(Round to three decimal places asneeded.)

How can the coefficient of determination beinterpreted?

A.

The coefficient of determination is the fraction of the variation in sales that is unexplained and is due to other factors or sampling error. The remaining fraction of the variation is explained by the variation in total square footage.

B.

The coefficient of determination is the fraction of the variation in sales that can be explained by the variation in total square footage. The remaining fraction of the variation is unexplained and is due to other factors or to sampling error.

(b) Find the standard error of estimate se and interpret the result.

(Round the final answer to three decimal places as needed. Round all intermediate values to four decimal places asneeded.)

How can the standard error of estimate beinterpreted?

A.

The standard error of estimate of the sales for a specific total square footage is about se billion dollars.

B.

The standard error of estimate of the total square footage for a specific number of sales is about se billion dollars.

2.The table shows the average weekly wages(in dollars) for state government employees and federal government employees for 8 years. The equation of the regression line is

y=1.541x126.639. Complete parts(a) and(b) below.

Average Weekly Wages(state),

x

746

768

792

820

842

886

916

947

Average Weekly Wages(federal),

y

991

1041

1116

1149

1203

1258

1284

1298

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

r2=

(Round to three decimal places asneeded.)

How can the coefficient of determination beinterpreted?

The coefficient of determination is the fraction of the variation in average weekly wages for (1) that can be explained by the variation in average weekly wages for (2) and is represented by (3) The remaining fraction of thevariation, (4), is unexplained and is due to other factors or to sampling error.

(b) Find the standard error of estimate se and interpret the result.

se=

(Round to two decimal places asneeded.)

How can the standard error of estimate beinterpreted?

The standard error of estimate of the average weekly wage for (5) for (6) average weekly wage for (7) is about se dollars.

(1)state government employees

federal government employees

all government employees in the last 8 years

(2)state government employees

federal government employees

all government employees in the last 8 years

(3)r2.

1r2.

(4)r2

1r2

(5)state government employees

federal government employees

all government employees in the last 8 years

(6)a specific

any

the range of

(7)state government employees

federal government employees

all government employees in the last 8 years

3.The table shows the amounts of crude oil(in thousands of barrels perday) produced by a certain country and the amounts of crude oil(in thousands of barrels perday) imported by the same country for seven years. The equation of the regression line is

y=1.272x+16,695.40. Complete parts(a) and(b) below.

Produced,

x

5,810

5,737

5,634

5,430

5,225

5,160

5,068

Imported,

y

9,328

9,153

9,615

10,014

10,194

10,100

10,055

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

r2=

(Round to three decimal places asneeded.)

How can the coefficient of determination beinterpreted?

The fraction of the variation in the amount of (1) that can be explained by the variation in the amount of (2) is (3) The remaining fraction (4) of the variation is unexplained and is due to other factors or to sampling error.

(b) Find the standard error of estimate se and interpret the result.

thousands of barrels per day

(Round to three decimal places asneeded.)

How can the standard error of estimate beinterpreted?

The standard error of estimate of the amount of (5) for (6) of (7) is about se (8)

(1)imported crude oil

produced crude oil

(2)imported crude oil

produced crude oil

(3)r2.

1r2.

(4)r2

1r2

(5)imported crude oil

produced crude oil

(6)a specific amount

any amount

any amount within the range of the data set

(7)imported crude oil

produced crude oil

(8)thousand of barrels per day.

thousand of barrels per year.

thousand of barrels.