Test a claim that the mean amount of carbon monoxide in the air in U.S. cities is less than 2.34 parts per million. It was found that the mean amount of carbon monoxide in the air for the random sample of 62 cities is 2.41 parts per million and the standard deviation is 2.12 parts per million. At =0.05, can the claim besupported? Complete parts(a) through(e) below. Assume the population is normally distributed.

(a) Identify the claim and state H0 and Ha. Which of the following correctly states H0 and Ha?

H0:

mu

sigma

p

p

sigma squared

2

less than or equals

less than

<

greater than or equals

not equals

greater than

>

equals

=

nothing

Ha:

sigma

mu

sigma squared

2

p

p

less than or equals

greater than or equals

equals

=

less than

<

greater than

>

not equals

nothing

(Type integers or decimals. Do notround.)

The claim is the

null

alternative

hypothesis.

(b) Use technology to find the criticalvalue(s) and identify the rejectionregion(s).

The criticalvalue(s) is/are t0=

nothing

.

(Use a comma to separate answers as needed. Round to two decimal places asneeded.)

Choose the graph which shows the rejection region.

A graph labeled negative t 0 less than t less than t 0 has a horizontal t-axis labeled from negative 4 to 4 in increments of 4. A symmetric bell shaped t-distribution curve is above the t-axis and centered on 0. Two vertical line segments extend from the curve to the t-axis at the points labeled negative t 0 and t 0, where t 0 is to the right of 0. The area under the curve between negative t 0 and t 0 is shaded.

A graph labeled t greater than t 0 has a horizontal t-axis labeled from negative 4 to 4 in increments of 4. A symmetric bell shaped t-distribution curve is above the t-axis and centered on 0. A vertical line segment extends from the curve to the t-axis at a point labeled t 0, where t 0 is to the right of 0. The area under the curve to the right of t 0 is shaded.