Question

6.

The data show the time intervals after an eruption​ (to the next​ eruption) of a certain geyser. Find the regression​ equation, letting the first variable be the independent​ (x) variable. Find the best predicted time of the interval after an eruption given that the current eruption has a height of 149 feet.

Height​ (ft)	108	124	108	152	109	138	137	103
Interval after​ (min)	77	73	81	87	69	91	90	68

What is the regression​ equation?

​ (Round to two decimal places as​ needed.)

What is the best predicted​ value?

​(Round to one decimal place as​ needed.)

7.

The data show the chest size and weight of several bears. Find the regression​ equation, letting chest size be the independent​ (x) variable. Then find the best predicted weight of a bear with a chest size of 40 inches. Is the result close to the actual weight of 382 ​pounds?

Chest size​ (inches)	41	54	44	55	39	51
Weight​ (pounds)	328	528	418	580	296	503

What is the regression​ equation?

​ (Round to one decimal place as​ needed.)

What is the best predicted weight of a bear with a chest size of 40​ inches?

​(Round to one decimal place as​ needed.)

Is the result close to the actual weight of 382 ​pounds?

A.

This result is exactly the same as the actual weight of the bear.

B.

This result is very close to the actual weight of the bear.

C.

This result is not very close to the actual weight of the bear.

D.

This result is close to the actual weight of the bear.

8.

If we find that there is a linear correlation between the concentration of carbon dioxide in our atmosphere and the global​ temperature, does that indicate that changes in the concentration of carbon dioxide cause changes in the global​ temperature?

Choose the correct answer below.

A.

No. The presence of a linear correlation between two variables does not imply that one of the variables is the cause of the other variable.

B.

Yes. The presence of a linear correlation between two variables implies that one of the variables is the cause of the other variable.

9.

Use the given data set to complete parts​ (a) through​ (c) below.​ (Use

alphaαequals=​0.05.)

x	10	8	13	9	11	14	6	4	12	7	5
y	9.15	8.15	8.74	8.78	9.26	8.11	6.12	3.11	9.13	7.25	4.74

a. Construct a scatterplot. Choose the correct graph below.

A.

04812160246810xy

A scatterplot has a horizontal x-scale from 0 to 16 in increments of 2 and a vertical y-scale from 0 to 10 in increments of 1. Eleven points are plotted with approximate coordinates as follows: (4, 2); (5, 2.6); (6, 3); (7, 3.6); (8, 4); (9, 4.6); (10, 5); (11, 5.6); (12, 6); (13, 6.6); (14, 7).

B.

04812160246810xy

A scatterplot has a horizontal x-scale from 0 to 16 in increments of 2 and a vertical y-scale from 0 to 10 in increments of 1. Eleven points are plotted with approximate coordinates as follows: (4, 3.2); (5, 4.8); (6, 6.2); (7, 7.2); (8, 8.2); (9, 8.8); (10, 9.2); (11, 9.2); (12, 9.2); (13, 8.8); (14, 8.2).

C.

04812160246810xy

A scatterplot has a horizontal x-scale from 0 to 16 in increments of 2 and a vertical y-scale from 0 to 10 in increments of 1. Eleven points are plotted with approximate coordinates as follows: (4, 6); (5, 5.6); (6, 5); (7, 4.6); (8, 4); (9, 3.6); (10, 3); (11, 2.6); (12, 2); (13, 1.6); (14, 1).

D.

04812160246810xy

A scatterplot has a horizontal x-scale from 0 to 16 in increments of 2 and a vertical y-scale from 0 to 10 in increments of 1. Eleven points are plotted with approximate coordinates as follows: (4, 1); (5, 1.4); (6, 1.6); (7, 2); (8, 2.4); (9, 3); (10, 3.6); (11, 4.2); (12, 4.8); (13, 6); (14, 8).

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

The linear correlation coefficient is

r equals =

​(Round to three decimal places as​ needed.)

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

A.

The scatterplot reveals a distinct pattern that is a​ straight-line pattern with negative slope.

B.

The scatterplot reveals a distinct pattern that is not a​ straight-line pattern.

C.

The scatterplot does not reveal a distinct pattern.

D.

The scatterplot reveals a distinct pattern that is a​ straight-line pattern with positive slope.

Answer 1

Q6.