Q1) You are manager of the restaurant which delivers pizza to college dormitory rooms. You have just modified your delivery process in the effort to increase mean time between order and completion of delivery from current 25 minutes. From past experience, you can suppose that population standard deviation is 6 minutes. Sample of 36 orders using new delivery process yields sample mean of 22.4 minutes.
i) Using six-step critical value approach, at the 0.05 level of significance, is there evidence that population mean delivery time has been increased below previous population mean value of 25 minutes?
ii) At the 0.05 level of significance, use five-step p-value approach.
iii) Interpret meaning of the p-value in (b).
iv) Compare your conclusions in (a) and (b).