Question

Do people walk faster in the airport when they are departing​ (getting on a​ plane) or do they walk faster when they are arriving​ (getting off a​ plane)? A reputable researcher measured the walking speed of random travelers in two International Airports. His findings are summarized in the table. Complete parts ​(a)-(c) below.

Direction of Travel	Departure	Arrival
Mean speed ​(feet per​ minute)	252	269
Standard deviation​(feet per​ minute)	50	31
Sample size 35 35

​(a) Is this an observational study or a designed​ experiment? Why?

A.

This is a designed experiment since the researcher did not influence the data.

B.

This is an observational study since the researcher influenced the data.

C.

This is a designed experiment since the researcher influenced the data.

D.

This is an observational study since the researcher did not influence the data.

​(b) Explain why it is reasonable to use​ Welch's t-test.

A.

The samples are​ random, large and dependent.

B.

The samples are​ random, large and independent.

C.

The populations are normally distributed.

D.

The samples are​ random, small and independent.

​(c) Do individuals walk at different speeds depending on whether they are departing or arriving at the α=0.05 level of​ significance? Let μ1 represent the mean speed of people departing and

μ2 represent the mean speed of people arriving.

State the null and alternative hypothesis.

A.

H0​: μ1<μ2

H1​: μ1>μ2

B.

H0​: μ1=μ2

H1​: μ1>μ2

C.

H0​: μ1=μ2

H1​: μ1<μ2

D.

H0​: μ1=μ2

H1​: μ1≠μ2

Determine the​ P-value for this hypothesis test.

​P-value=__?__

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

Choose the correct conclusion.

A.

Do not reject H0. There is not sufficient evidence at the α=0.05 level of significance to say that travelers walk at different speeds depending on whether they are arriving or departing.

B.

Reject H0. There is not sufficient evidence at the α=0.05 level of significance to say that travelers walk at different speeds depending on whether they are arriving or departing.

C.

Do not reject H0. There is sufficient evidence at the α=0.05 level of significance to say that travelers walk at different speeds depending on whether they are arriving or departing.

D.

Reject H0. There is sufficient evidence at the α=0.05 level of significance to say that travelers walk at different speeds depending on whether they are arriving or departing.

Answer 1