hi there, can you please help me answer these project management questions ? starting from number 4 to number 8. thank you so much for you help

hi there, can you be more specific which regard your comments. everything regard the questions are all there on the picture. thank you

Activities Immediate Duration T.= (a+4m+b)/6 = (b-a)/6 Predecessor PESSIMISTIC A(OPTIMISTIC NORMAL 3 5 6 A Existing 20 item removal B. Electrician A11 3 3 4 7 C. Painting AS 1 1 3 5 . 2 4 7 D. Wallpaper B4 installer 02 2 5 8 E.New furniture- Place in the position as the design plan 2 F. Install new D2 furniture, chair and dining table G. Completion E 1 2 3 4 1. Draw the Activity on Arrow network diagram for this project 2. The mean and standard deviation for each activity 3. Calculate the mean and standard deviation for each path 4. Identify the critical path and its expected length 10 10 5 2 5. From the information listed in the table, Draw a pareto diagram reflecting the respective defects. Activity Defects A 20 B B 11 5 D 4 E 2 F 2 G G 1 10 6. Investigate the activity with the highest defect by drawing a fishbone or cause and effectto highlight the possible cause to the problem 10 7. Provide possible solutions to the cause/s identified 3 8. Differentiate between quality assurance and quality control 15