Assume an uncertain task has a duration that is characterized by a beta distribution. Assume values for a $($optimistic$),$ m $($most likely$)$ and b $($pessimistic$)$ duration to

be $30,50$ and $130.$ What is the mean the completion time? $\{$HINT: mean $=($a $+4$m $+$ b$)/6.\}$

O a$.50$

$$ b$.45$

$$ d$.60$

$0$ e$.55$

O c$.$ None of these alternative is correct.