please solve in excel and show step by step

Q4. (15 points) The Ringtones, a gospel rock group that had many record hits in the 1970s, has evolved and changed many musicians over the past decades. A group however is still singing and performing at music concerts under that name and is now touring Canada. The Ringtones would like to stop in Montreal, Quebec on its current tour schedule. A local music station, PQSR, is in charge of making the arrangements to bring the group to Montreal. The station has listed the following activities that must be completed prior to the music concert in the table that follows. Time is measured in weeks. Activity Immediate Optimistic Most Pessimistic Predecessors Likely A. Negotiate lease/contract terms 4 5 B. Hire opening music acts A 12 C. Hire concert security B 3 D. Hire sound technicians B 10 E. Ticket sales outlets B 4 U NA U N N N - NW C U - W W W N A F. Initial sales promotion E 4 G. Hotel/travel arrangements A 1.5 H. Final sales promotion F 12 Concert rehearsals C. D. G 8 J. Concession sales A 13 15 a. Give an estimated completion time for this project. Show calculations. b. Which activities have the most slack? c. What is the probability that the project will be completed in 12 weeks? d. Give a time in which the station can be 99% sure of completing the project