Question

An automobile manufacturer claims that their jeep has a 43.5 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this jeep. After testing 17 jeeps they found a mean MPG of 43.7 with a variance of 6.25. Is there sufficient evidence at the 0.1 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

The statistical software output for this problem is:

From above output:

Step - 1: Hypotheses:

Ho: = 43.5

Ha: > 43.5

Step - 2: Test statistic = 0.330

Step - 3: One tailed test

Step - 4: Reject Ho if t > 1.337

Step - 5: Fail to reject Null Hypothesis