Given the data below for construction project, based on a PERT analysis:

$-$ What is the expected project duration $[15$ Points$]?$ Show your calculation on the network

$-$ Determine the probability of finishing the project in:

$($a$)$ In longer than $+2$ days $[5$ Points$],($b$)$ between more than $+2$ and less than $+4$ days $[5$ Marks$].$

$-$ What is the project duration with probability of $(70\%)[5$ Marks$].$