Expected time (t) is calculated using the following formula: t = (a + 4m + b) / 6, where
a = optimistic time estimate (in this case 2); m = most likely time estimate (in this case 3); and b = pessimistic time estimate (in this case 8). Therefore;
t = (2 + 4³ + 8) / 6
t = 22 / 6
t = 3.67
