Use the 5 step method. The \"9-Minute Oil Change\" company advertises that the a

Question

Use the 5 step method.

The "9-Minute Oil Change" company advertises that the average wait for an oil change at their stations is 9 minutes. A consumer advocate group has had reports from customers that they usually have to wait longer than 9 minutes. In order to test the company's claim, 50 customers were randomly selected and the time required for their oil change was recorded. For this sample, the average wait for an oil change was 11 minutes with an SD of 5 minutes. Is there significant eveidence that the average wait for all customers is greater than 9 minutes?

Explanation / Answer

H0: average wait = 9 minutes

H1: average wait > 9 minutes

t=(11-9)/(5/50) 

=2.83

P-value = P(t>2.83)=0.0001

Since the p-value is very low we can reject H0 and

conclude that the average wait for all customers is greater than 9 minutes.

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.