Answer:
The percentage yield is 90.9 % (option e)
Step-by-step explanation:
A simple rule of three to explain this.
If the theoretical yield of the reaction is 47.2 g Fe, we assume it as 100%, then what percentage of yield means 42.9 g Fe
47.2 g Fe _____ 100 %
42.9 g Fe ______ ( 42.9 . 100)/ 47.2 = 90.88%