In 2008, a small dealership leased 21 Suburu Outbacks on 2-year leases. When the cars were returned in 2010, the mileage was recorded (see below).

1. Find the sample mean with 90% confidence interval.

2. Is the dealer's mean significantly greater than the national average of 30,000 miles for 2-year leased vehicles, using the 5 percent level of significance?

Find answer using the following steps :

Find answer using the following steps :

Step 1: State the Hypotheses

Step 2: Specify the Decision Rule

Step 3: Calculate the Test Statistic

Step 4: Make the Decision

Calculate p-value also and give interpretations.

Data:

40,060 24,960 14,310 17,370 44,740 44,550 20,250

33,380 24,270 41,740 58,630 35,830 25,750 28,910

25,090 43,380 23,940 43,510 53,680 31,810 36,780

These questions should be answered in a plain language, executive level report that is supported with a technical level appendix that includes the original data set, all manipulations and calculations of those data in Excel®, all relevant statistical software output, and a running narrative explaining the methodology used, the assumptions made, and the interpretation of each analysis performed. Use only the information provided and your business and or common sense to complete this project; do not make things up or engage in creative writing.