A sample of 60 chewable vitamin tablets have a sample mean of 275 milligrams of vitamin C. Nutritionists want to perform a hypothesis test to determine how strong the evidence is that the mean mass of vitamin C per tablet exceeds 272 milligrams. State the appropriate null and alternate hypotheses.

A grocery store owner claims that the mean amount spent per checkout is more than $74. A test is made of Ho: μ = 74 versus H1: μ > 74. The null hypothesis is rejected. State the appropriate conclusion.

A fleet of rental cars - all the same make, model, and year - has a mean fuel efficiency of 24 miles per gallon (mpg). A random sample of 44 cars are selected and the air filter of each is replaced with a new one. Let μ 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 μ> 24 mpg. A test is made of Ho: μ = 24 versus H1 : μ > 24 . Which of the three conclusions is the best if Ho is rejected? Consider these possible conclusions: