Operations Management help needed. please check your work, provide explanation if possible. if it's right I'll give you a like.

The MM1 model is modeled to have exponential service time (random). On the other hand, the MD1 model is know to have deterministic service times (constant). By experimenting in Q.xls which of the below seems to be (and in fact is) true? Constant service time model will have an average queue length and an average waiting time that is twice that of the same model with exponential service time. Constant service time model will have an average queue length and an average waiting time that is equal to that of the same model with exponential service time. Constant service time model will have an average queue length and an average waitin time that is one-half that of the same model with exponential service time. Constant service time model will have an average queue length and an average waiti time that is triple that of the same model with exponential service time. None of the above