You're the manager of restaurant which delivers pizza to college dormitory rooms. You've just changed your delivery procedure in an effort to reduce the mean time between the order and completion of delivery from current 25 minutes. From past experience, you can suppose that the population standard deviation is six minutes. A sample of 36 orders using the new delivery procedure yields a sample mean of 22.4 minutes.

1. Using the 6-step critical value approach, at the 0.05 level of significance, is there evidence that the population mean delivery time has been reduced below previous population mean value of 25 minutes?
2. At the 0.05 level of importance, use the five-step p-value approach.
3. Interpret the meaning of p-value in (b).
4. Compare your conclusions in (a) and (b).