An activity on a PERT network has these time estimates: optimistic =2, most likely =3, and pescinistic =8 is eperain ine and variance are Expected time is 4.33 and variance is 1 Expected time is 3.67 and variance is 6 None of the answers shown here are correct Expected time is 3.67 and variance is 1 d time is 4.33 and variance is 6