A company guarantees a $95\%$ cycle$-$service level for all of its stock items. The company replenishes its stock from a single supplier who guarantees a lead time of $4$ weeks. For an item with a normally distributed demand, the mean demand per week is $900$ units, and the standard deviation of demand is $100$ units. What should be the reorder level for this item to maintain a $95\%$ cycle$-$service level? Additionally, what should be the reorder level for this item to maintain a $98\%$ cycle$-$service level?