Operators of gasoline-fueled vehicles complain about the

Chapter 10, Problem 65E

(choose chapter or problem)

Operators of gasoline-fueled vehicles complain about the price of gasoline in gas stations. According to the American Petroleum Institute, the federal gas tax per gallon is constant (\(18.4\ \text{¢}\) as of January 13,2005 ), but state and local taxes vary from \(7.5\ \text{¢}\) to \(32.10\ \text{¢}\) for n = 18 key metropolitan areas around the country. The total tax per gallon for gasoline at each of these 18 locations is given next. Suppose that these measurements constitute a random sample of size 18 :

42.89     53.91     48.55     47.90     47.73     46.61

40.45     39.65     38.65     37.95     36.80     35.95

35.09     35.04     34.95     33.45     28.99     27.45            

a. Is there sufficient evidence to claim that the average per gallon gas tax is less than \(45\ \text{¢}\)? Use the \(t\) table in the appendix to bound the p-value associated with the test.

b. Applet Exercise What is the exact p-value?

c. Construct a 95% confidence interval for the average per gallon gas tax in the United States.

Equation Transcription:

 ¢  

 

 ¢

 ¢    

 

 ¢

Transcription:

18.4 cent    

7.5 cent

32.10 cent      

45 cent  

t