Answer:
68.6 %; 72.1 %
Explanation:
The overall percentage yield for a multi-step synthesis is the product of the percentage yields for each individual step.
For the three-step synthesis
Overall yield = 0.872 × 0.911 × 0.863 = 0.686 =68.6 %
For the two-step synthesis,
Overall yield = 0.855 × 0.843 = 0.720 = 72.1 %