kindly answer urgently step by step

This is a subjective question, hence you have to write your answer in the Text-Field given below. Daily demand for PCs at HP is normally distributed, with a mean of 5,000 and a standard deviation of 200 . A key component in PC assembly is the hard drive. The hard drive supplier takes an average of L=5 days to replenish inventory at HP. HP is targeting a CSL of 90 percent for its hard drive inventory. Evaluate the safety inventory of hard drives that HP must carry if the standard deviation of the lead time is four days. HP is working with the supplier to reduce the standard deviation to two. Evaluate the reduction in safety inventory that HP can expect as a result of this initiative. [F1(90)=1.28] [4+3]