Another department of motor vehicles office claims that the mean wait time is at most 18 minutes. A random sample of 12 people has a mean wait time of 15 minutes with a standard deviation of 2.2 minutes. At α = 0.05, test the office’s claim. Assume the population is normally distributed.
a. Identify the claim and state H0 and Ha.
b. Use technology to find the P-value.
c. Compare the P-value with the level of significance a and make a decision.
d. Interpret the decision in the context of the original claim.