A manufacturing project has five independent phases Mean (hours) Std. Dev. (hours) Set up dies and other tools 17 2 Milling and machining 9 4 Finishing and painting 15 6 Packing and crating 7 5 Shipping 43 5 A manufacturing project has ve independent phases whose completion must be sequential. The time to complete each phase is a random variable. The mean and standard deviation of the time for each phase are shown below. Phase Mean (hours) Std. Dev. (hours) Set up dies and other tools 17 2 Milling and machining 9 4 Finishing and painting 15 6 Packing and crating 7 5 Shipping 43 5 'Click here for the Excel Data File (a) Find the expected completion time. The expected completion time hours (b) Make a 2-sigma interval around the mean completion time (1' i 20]. (Round your answers to 1 decimal place.) 2-sigma range to