Please provide a clear step by step solution. Thank you!!

Question 3. A popular Cheap-Ticket flight from New York (LGA) to Dallas (DFW) costs $120. The airline knows that an average of 20 customers (with a standard deviation of 10 customers) cancel their reservations from history. I the flight is overbooked, the airline has the policy to board the customer on the next available flight and give the person a free round-trip ticket on a future flight. The cost of free round-trip flight averages $180. By how many should this 'Cheap-Ticket' airline overbook the flight (sale extra ticket)? Suggestion Step 1: Find the P-value (probability): P = Cu/(Cu + Co) = (value) Step 2: Find Z-value using Excel NORMSINV (P-value) From normal table, P = value correspond to Z value = (value) Step 3: Find X-value (u and o known) from the equation: Substituting Z = (value) to find the X = ? Z= (X-p)/o or, X= Z*o +p 0 4 O 15 0 6 O 17