Activity	Personnel	Description	Immediate Predecessor	Optimistic	Most Likely	Pessimistic
A	Anesthesiologist	Transport Patient 1 to PACU	N/A	2	2	2
B	Anesthesiologist	Clean up and prepare for the next surgery	A	29	37	57
C	Surgeon	Surgeon preparation for next surgery	A	7	15	35
D	Surgery RN	RN preparation for next surgery	A	20	32	42
E	Scrub Tech	Scrub Tech break down tasks	A	5	10	15
F	Scrub Tech	Sterile tasks	G, E	12	30	37
G	Orderly Team	Orderly task	A	3	7	15
H	Anesthesia Tech	Anesthesia tasks for next surgery	A	15	27	35
I	Pre-op RN	Preop checklist for patient 2	B, C, D, F	5	10	20
J	Surgeon and Surgery RN	Transport patient 2 to OR	I	2	2	2

4. Draw a graph that the y-axis is the probability that the ORTOT is longer than a given time t, and the x-axis is t. Let t varies from 44 to 64 minutes in an increment of 2 minutes.

5. Use the data from the Excel file named Historial ORTOT to draw the second curve on the graph of question 4. Combine the data from year 1 and year 2. Explain why your PERT analysis does not match the historical data.

6. Get rid of the outliers in the historical data with special code and try again to see whether they match. Explain to what extend your PERT analysis is validated now and can be used for further analysis and why it is important to validate your PERT model against historical data.