The mean age of all

696

used cars for sale in a newspaper one Saturday last month was

7.8

years, with a standard deviation of

7.5

years. The distribution of ages is right-skewed. For a study to determine the reliability of classified ads, a reporter randomly selects

50

of these used cars and plans to visit each owner to inspect the cars. He finds that the mean age of the

50

cars he samples is

8.4

years and the standard deviation of those

50

cars is

6

years. Complete parts a through c.

Question content area bottom

Part 1

a. From the problem statement, which of the values

7.8,

7.5,

8.4,

and

6

are parameters and which are statistics?

The value

7.8

is a

parameter.

The value

7.5

is a

parameter.

The value

8.4

is a

statistic.

The value

6

is a

statistic.

Part 2

b. Find

,

,

s, and

x.

=enter your response here

=enter your response here

s=enter your response here

x=enter your response here

(Type integers or decimals.)

Part 3

c. Are the conditions for using the CLT (Central Limit Theorem) fulfilled?

A.

No, because the random sample/independence and Normal conditions are not fulfilled.

B.

No, because the random sample/independence condition is not fulfilled.

C.

No, because the Normal condition is not fulfilled.

D.

Yes, all the conditions for using the CLT are fulfilled.

Part 4

What would be the shape of the approximate sampling distribution of a large number of means, each from a sample of

50

cars?

Right-skewed

Left-skewed

Normal

Uniform

The shape cannot be determined.