A scientist estimates that the mean nitrogen dioxide level in a city is greater than

2525

parts per billion. To test this estimate, you determine the nitrogen dioxide levels for 31 randomly selected days. The results (in parts per billion) are listed to the right. Assume that the population standard deviation is

1111.

At

alphaequals=0.110.11,

can you support the scientist's estimate? Complete parts (a) through (e).

1919	2424	3838	1616	4242	4444	2929	2424	2222	2222	4242
2525	2525	1414	2121	4343	4141	2424	2424	4444	1515	2323
3333	2323	3636	3535	2222	3737	1414	4242	2020

Question content area bottom

Part 1

(a) Write the claim mathematically and identify

Upper H 0H0

and

Upper H Subscript aHa.

Choose from the following.

A.

Upper H 0H0:

mugreater than or equals2525

(claim)

Upper H Subscript aHa:

muless than<2525

B.

Upper H 0H0:

muless than<2525

Upper H Subscript aHa:

mugreater than or equals2525

(claim)

C.

Upper H 0H0:

muequals=2525

Upper H Subscript aHa:

mugreater than>2525

(claim)

D.

Upper H 0H0:

muequals=2525

(claim)

Upper H Subscript aHa:

mugreater than>2525

E.

Upper H 0H0:

muless than or equals2525

Upper H Subscript aHa:

mugreater than>2525

(claim)

F.

Upper H 0H0:

muless than or equals2525

(claim)

Upper H Subscript aHa:

mugreater than>2525

(b) Find the critical value and identify the rejection region.

z 0z0equals=enter your response here

(Round to two decimal places as needed.)

Rejection region:

z

enter your response here

(c) Find the standardized test statistic.

zequals=enter your response here

(Round to two decimal places as needed.)

(d) Decide whether to reject or fail to reject the null hypothesis.

Fail to reject Upper H 0

Fail to rejectFailtoreject

Upper H 0H0

Reject Upper H 0

RejectReject

Upper H 0H0

(e) Interpret the decision in the context of the original claim.

At the

1111%

significance level, there

enough evidence to

the scientist's claim that the mean nitrogen dioxide level in the city is greater than

2525

parts per billion.