Question 4: (10 marks) (B1, C3) Zani Newsagents stocks a weekly lifestyle magazine. The owner buys the magazines at the beginning of each week for $0.40 each and sells them at the retail price of $0.60 each. At the end of the week, unsold magazines are obsolete and have no value, so they are discarded as recycled waste. The estimated probability distribution for weekly demand is as follows: Weekly demand in units 30 40 50 Probability 0.15 0.45 0.40 1.00 The actual demand in each week does not affect the actual demand in the following week. Instructions: If the owner is to order a fixed quantity of magazines per week, how many should that be