Weekly demand for EPSON printers at a WALMART store is normally distributed with a mean of 280 and a standard deviation of 180. The store manager continuously monitors inventory and currently orders 1,100 printers each time the inventory drops to 700 printers. EPSON currently takes two weeks to fill an order. How much safety inventory should WALMART carry? What is the Cycle Service Level (CSL)? What is the expected shortage per replenishment cycle (ESC)? What is the fill rate (fr)?

I am trying to figure out the math behind this problem, if you could show me step by step I would really appreciate it. I know it has to do with EOQ!