I would like to ask for the solving for Part (b).

Question 2 Revenue Management During the pandemic, a hotel with 200 rooms offers two rates: a full price of 800 HKD and a discount price of 650 HKD. To receive the discount price, a customer must book the room through the hotel's staycation plan, which requires her to place the order at least two weeks in advance. For a particular Tuesday night, the hotel estimates that the demand from staycation customers could fill the whole hotel while the demand from business travelers (who values the flexibility of booking late and can never book two weeks in advance) follows a certain distribution. a. Find the optimal protection level for full price rooms. Suppose the demand from business travelers follows a normal distribution with mean = 80 and standard deviation = 35. b. The hotel decides to reserve 50 rooms for business travelers. The estimated number of unfilled rooms is 4.22 on average. What is revenue difference between this policy and the policy without protection