An energy company wants to choose between two regions in a state to install? energy-producing wind turbines. A researcher claims that the wind speed in Region A is less than the wind speed in Region B. To test the? regions, the average wind speed is calculated for 60 days in each region. The mean wind speed in Region A is 13.9 miles per hour. Assume the population standard deviation is 2.9 miles per hour. The mean wind speed in Region B is 15.1 miles per hour. Assume the population standard deviation is 3.1 miles per hour. At α=0.05?, can the company support the? researcher's claim? Complete parts? (a) through? (d) below.
(a) Identify the claim and state H0 and Ha.
(b) Find the critical? value(s) and identify the rejection region
(c) Find the standardized test statistic z.
(d) Decide whether to reject or fail to reject the null hypothesis and interpret the decision in the context of the original claim.