A manufacturer claims that a particular automobile model will get 50 miles per gallon on the highway. The researchers at a consumer-oriented magazine believe that this claim is high and plan a test with a simple random sample of 30 cars. Assuming the standard deviation between individual cars is 2.3 miles per gallon, what should the researchers conclude if the sample mean is 49 miles per gallon?
- The P-value of .0087 is sufficient evidence to reject the manufacturer's claim.
- There is not sufficient evidence to reject the manufacturer's claim; 49 miles per gallon is close to the claimed 50 miles per gallon.
- The manufacturer's claim should be rejected because the sample mean is less than the claimed mean.
- The manufacturer's claim should not be rejected because the P-value is too small.
- The P-value of .0087 is sufficient evidence to prove that the manufacturer's claim was a lie.