only the second question please

The mean and standard devation of a process are xbar = 90 and o =6. For the varables control chart, a sample eize of 16 wit be uesd. What is the standard deviaton of the dis tritution of the aample mwrape. x-ber? a. 11.37 b. 4 e. 8 d. 2 An inventory decision rule is to "place an order for 500 units whenever the hventory level goes down ta 55 ," Which of the following statements ha true? a. the order point is 65, and the order quantity is 500 b. 55 is the safety stock, and the re-order point is 500 c. 500 is the re-order point, and 55 is the ovder quantity d. 500 is the salety stcok, and 55 is the re-order point