A university department maintains an emergency computer repair shop. History shows that broken computers arrive for repair randomly, but with average rates that depend on the number of computers that are already in the shop. The average arrival rates are shown below: no. computers already' In the shop 0 -IIIIEIEI The technician in the shop can repair computers at an average rate of 4 computers per day. However, whenever there are 3 or more computers in the shop for repair, an extra technician is used, and this doubles the average rate of computer repair to 8 computers per clay. a]: What is the probability that an extra technician is used? b] What is the expected number of computers in the shop awaiting service? c] The policy of using the extra technician was introduced because the shop wishes to return computers to users within a half-clay of the computers arrival in the shop, on average. What is the average amount of time that a computer is in the shop? Does the shop achieve its goal of returning computers to the users in a half-day or less