Please BOLD answers!

Already figured out answer to a. which is 733. Need assistance with parts b.- d. Answer to b is NOT 139.

percent of the item's cost. Your firm operates 6 days per week, 48 weeks per year. Refer to the standard normal table for z-values. a. What is the optimal ordering quantity for this item? units. (Enter your response rounded to the nearest whole number.) b. How many units of the item should be maintained as safety stock for 98 percent protection against stockouts during an order cycle? units. (Enter your response rounded to the nearest whole number.) c. If supply lead time can be reduced to 4 weeks, what is the percent reduction in the number of units maintained as safety stock for the same 98 percent stockout protection? %. (Enter your response rounded to two decimal places.) d. If through appropriate sales promotions, the demand variability is reduced so that the standard deviation of weekly demand is 11 units instead of 25 , what is the percent reduction (compared to that in part (b)) in the number of units maintained as safety stock for the same 98 percent stockout protection? \%. (Enter your response rounded to two decimal places.) The table below shows the total area under the normal curve for a point that is Z standard deviations to the right of the mean