QBP sources a specialty bike seat from a manufacturer in Germany and stocks this in its Bloomington DC$.$ Weekly demand for this bike seat is normally distributed with a mean of $60$ and standard deviation of $30$ which is fairly steady throughout the year. The seat manufacturer takes one week to supply a QBP order. QBP thinks it has been stocking this item too high and is looking for advice on using a periodic review inventory policy.$$ QBP would like to support an in$-$stock probability of $95\%$ on this item and plans to place replenishment orders once every two weeks.$$

How much safety stock should QBP DC target for this item?