num 9

A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of 23.4 miles per gallon (mpg). A random sample of 41 cars are selected and the air filter of each is replaced with a new one. Let be the population mean fuel efficiency score that would occur if every car's air filter were replaced. The air filter change is deemed effective if u>23.4mpg. A test is made of H0:u=23.4 versus H1:u>23.4.

Assume that the air filter changes are effective but the conclusion is reached that the changes might not be effective. Which type of error, of any, has occurred? Question 9 options:

Type I

No error - correct decision

Type II

Mechanical failure