An HVAC design engineer observed four cycles of an experienced worker installing a takeoff collar on the heating duct system. The engineer used continuous timing and recorded the observations in the following table along with a performance rating for each task. All times are in minutes. Cycle 1 2 3 4 PRF Cut hole 11 10 8 9 0.8 Insert collar 12 15 10 11 0.9 Fold down flaps 19 19 17 20 0.9 Apply sealant 22 24 25 29 1.1 What is the observed time for the Insert collar step? a. 2.5 minutes b. 7.6 minutes c. 12 minutes d. 2.25 minutes