1.The Global Business Travel Association reported the domestic airfare for business travel for the current year and the previous year. Below is a sample of 12 flights with their domestic airfares shown for both years.

Current Year

345

526

420

216

285

405

635

710

605

517

570

610

Previous Year

315

463

462

206

275

432

585

650

545

547

508

580

a.Is there evidence of an increase in the mean domestic airfare for business travel for the one-year period? Use a 0.05 level of significance.

b.What is the sample mean domestic airfare for business travel for each year?

c.What is the percentage change in the airfare for the one-year period?

2.The Nova Scotia Department of Transportation (DOT) wants to determine the average number of miles travelled by commuters in Halifax and Dartmouth to work. A random sample of 30 Halifax and 25 Dartmouth residents revealed the following:

Halifax

Dartmouth

Mean

12 km

15 km

Standard Deviation

5.75

2.55

Sample size

30

25

Some 15 years ago, it was found that both Halifax and Dartmouth Commuters travelled an averge of 8 km to work.

a.At a 5% significance level, is there sufficient evidence that the mean travel distance for Dartmouth commuters has increased? Use the classical approach.

b.[6] DOT now believes that commuters living in the twin cities no longer travel the same average distance to work. At a 10% significance level, is there sufficient evidence of a difference in the mean travel times for Dartmouth and Halifax commuters? Assume that the population variances are equal.

c.Repeat only your calculations and conclusions for part b WITHOUT the assumption.

3.[8] In 2019, 46% of business owners gave a holiday gift to their employees. A 2020 survey of business owners indicated that 35% planned to provide a holiday gift to their employees. Suppose the survey results are based on a sample of 60 business owners.

a.[2] How many business owners in the survey planned to provide a holiday gift to their employees in 2020?

b.[4] Suppose the business owners in the sample did as they planned. Compute the p-value for a hypothesis test that can be used to determine if the proportion of business owners providing holiday gift had decreased from the 2019 level.

c.[2] Using a 0.05 level of significance, would you conclude that the proportion of business owners providing gifts decreased? What is the smallest level of significance for which you could draw such a conclusion?

d.[6] DOT now believes that commuters living in the twin cities no longer travel the same average distance to work. At a 10% significance level, is there sufficient evidence of a difference in the mean travel times for Dartmouth and Halifax commuters? Assume that the population variances are equal.

e.Repeat only your calculations and conclusions for part b WITHOUT the assumption.

4.[16]A company is considering an organizational change by adopting the use of self-managed work teams. To assess the attitudes of employees of the company toward this change, a sample of 400 employees is selected and asked whether they favor the institution of self-managed work teams in the organization. Three responses were permitted: favor, neutral, or oppose. The results of the survey, cross-classified by type of job and attitude toward self-managed work teams, are summarized as follows:

Attitude Toward Self-managed Work Teams

Type of Job

Favor

Neutral

Oppose

Total

Hourly worker

108

46

71

225

Supervisor

18

12

30

60

Middle Management

35

14

26

75

Upper Management

24

7

9

40

Total

185

79

136

400

a.[9]At the 0.05 level of significance, is there evidence of a relationship between attitude toward self-managed work teams and type of job? Use a critical value and p-value approach as well as Minitab for the calculations and include the pertinent output.

b.[2] Would it be appropriate to conduct a Marascuillo procedure for this question? Explain.

c.[5] Using a significance level of 0.05, test to determine whether the proportion of Middle Management who favour self-managed work teams is significantly different from those who oppose it.