Economic/Statistic Problems

Problem 11-18 The Laurenster Corporation is getting into the con- struction business A list of activities and their optimistic, most likely, and pessimistic completion times are given in the following table for the next construction project. See table in uploads. (a) Develop a project network for this problem. (b) Determine the expected duration and variance for each activity. (c)Determine the ES, EF, LS, LF, and slack time for each activity. Also determine the total proj- ect completion time and critical path(s). (d) What is the probability that this job will finish in 38 days or less? Problem 11-19 The Laurenster Corporation needs to set up an as- sembly line to produce a new product. The fol- lowing table describes the relationships among the activities that need to be completed for this product to be manufactured. Table uploaded below (a) Develop a project network for this problem. (b)Determine the expected duration and variance for each activity. (c)Determine the ES, EF, LS, LF, and slack time for each activity. Also determine the total proj- ect completion time and the critical path(s). (d) Determine the probability that the project will be completed in 34 days or less. (e) Determine the probability that the project will take longer than 29 days. Problem 11-23 Tom Schriber, the director of personnel of Manage- ment Resources, Inc., is in the process of designing a program that its customers can use in the job-finding process. Some of the activities include preparing resumes, writing letters, making appointments to see prospective employers, and researching companies and industries. The information on these activities is shown in the following table: Uploaded below (a) Construct a network for this problem. (b)Determine the expected time and variance for each activity. (c)Determine ES, EF, LS, LF, and slack time for each activity. (d)Determine the critical path(s) and project corn- pletion time. (e)Determine the probability that the project will be finished in 70 days or less. (f)Determine the probability that the project will be finished in 80 days or less. (g)Determine the probability that the project will be finished in 90 days or less. Problem 11-35 The managing partner of the Scott Corey account-ing firm (see Problem 11-34) has decided that the system must be up and running in 16 weeks. Consequently, information about crashing the project was put together and is shown in the following table: (a)If the project is to be finished in 16 weeks, which activity or activities should be crashed to do this at the least additional cost? What is the total cost of this? (b)List all the paths in this network. After the crashing in part (a) has been done, what is the time required for each path? If the project completion time must be reduced another week so that the total time is 15 weeks, which activity or activities should be crashed? Solve this by inspection. Note that it is sometimes better to crash an activity