Question

An automobile manufacturer has given its van a 39.0 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the actual MPG for this van since it is believed that the van has an incorrect manufacturer's MPG rating. After testing 120 vans, they found a mean MPG of 38.8. Assume the population standard deviation is known to be 2.2. Is there sufficient evidence at the 0.02 level to support the testing firm's claim? Make the decision to reject or fail to reject the null hypothesis.
a. Reject Null Hypothesis
b. Fail to Reject Null Hypothesis

Answer 1

I know that the value of the test statistic is z= -1.00 given the information I just read from your upload.

I want to say B. Fail to Reject Null Hypothesis

But I'm not a 100% sure it's actually B