(b) The local electronics retailer is planning to hold a promotion event for its latest hot-seller OLED TV, for which it needs an inventory policy. A fixed cost of $2000 is incurred when the retailer places an order from the upstream distributor, and the lead time to receive the order is 15 days. In addition, the retailer has to rent extra warehouse to keep the TVs with a fixed daily holding cost of $10 per unit. The retailer estimated the daily demand of OLED TVs during the promotion period will be normally distributed with mean 4 and variance 1. (i) Determine the EOQ, and the reorder point. (ii) Determine the size of the buffer stock if the retailer wants to limit the probability of stock-out during the lead time to no more than 5%. (iii) It is believed that the demand during lead time is uniform over the range (0, 20) units. Determine the optimal inventory policy if the shortage cost is $500 per unit. Obtain the minimizer (y*, R*) in 1 decimal point.