21. Given the project information in the following table, what is the probability of completing the National Holiday Toy project in 99-time units? Hint: Use the =NORM.S.DIST(Z, TRUE) function in Excel to compute the probability. (Carry at least 3 decimal places in all intermediate calculations and the Z value. Enter your final probability answer to 3 decimal places.) Optimistic Most Pessimistic Activity Variance Acct. ID Description Predecessor (a) Likely (m) (b) Time (to) [(b-a)/6) Critical ? 1 Design package None 6 12 24 13 9 2 Design product 15 19 28 19.83 4.69 3 Build package 4 7 10 7 1 4 Secure patent 21 30 39 30 9 Build product 2 17 29 47 30 25 Paint 3,4,5 4 7 12 7.33 1.78 7 Test market 13 14 19 14.67 NON X X X