Question

An automobile manufacturer has given its jeep a 52.8 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the actual MPG for this jeep since it is believed that the jeep has an incorrect manufacturer's MPG rating. After testing 230 jeeps, they found a mean MPG of 52.7. Assume the population standard deviation is known to be 1.0. Is there sufficient evidence at the 0.1 level to support the testing firm's claim?

State the null and alternative hypotheses.

Find the value of the test statistic. Round your answer to two decimal places.

Specify if the test is one-tailed or two-tailed.

Find the P-value of the test statistic. Round your answer to four decimal places.

Identify the level of significance for the hypothesis test.

Make the decision to reject or fail to reject the null hypothesis.

Answer 1

The statistical software output for this problem is:

Hence,

Hypotheses:

Ho: = 52.8

Ha: 52.8

Test statistic = -1.52

This test is two - tailed

P-value = 0.1294

Level of significance = 0.1

Decision: Reject the null hypothesis