Question

An automobile manufacturer claims that their van has a 45.945.9 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this van. After testing 1111 vans they found a mean MPG of 45.745.7 with a variance of 2.892.89. Is there sufficient evidence at the 0.0250.025 level that the vans underperform 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

This is a one tailed test as the alternative hypothesis contains " < " sign.