Question

An automobile manufacturer claims that their jeep has a 55.355.3 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this jeep. After testing 1515 jeeps they found a mean MPG of 55.555.5 with a variance of 6.256.25. Is there sufficient evidence at the 0.050.05 level that the jeeps outperform the manufacturer's MPG rating? Assume the population distribution is approximately normal.

Step 1 of 5: State the null and alternative hypotheses.

Step 2 of 5: Find the value of the test statistic. Round your answer to three decimal places.

Step 3 of 5: Specify if the test is one-tailed or two-tailed.

Step 4 of 5: Determine the decision rule for rejecting the null hypothesis. Round your answer to three decimal places.

Step 5 of 5: Make the decision to reject or fail to reject the null hypothesis.

Answer 1