$($a$)$ Develop an activity schedule for this project and identify the critical path activities. $($Enter your answers as a comma$-$separated list.$)$

$($b$)$ Based solely on the critical path, what is the probability that the project will be completed so that Landon Corporation may introduce the new product within $26$ weeks? $($You may need to use the appropriate technology to answer this question. Round your answer to four decimal places.$)$

$($c$)$ Based solely on the critical path, what is the probability that the project will be completed so that Landon Corporation may introduce the new product within $30$ weeks? $($You may need to use the appropriate technology to answer this question. Round your answer to four decimal places.$)$