Calculations without Excel would be appreciated

Three estimates for the time require to complete each activity for a project is given in table 3 below. i. Calculate the expected value and standard deviation of the time required for each activity. Explain whether the project will be completed in time. ii. Activity Optimistic Time (minutes) Most Likely Pessimistic Time Time (minutes) (minutes) 1+2 28 32 36 1+3 22 28 32 2 +6 26 36 46 34 14 16 18 3 +5 32 32 32 3 6 40 52 74 -> 16 24 4 5 5+6 12 16 20 5 +7 26 34 16 26 42 30 6 +7 12 Table 3