Final answer:
The student needs to provide the transformation rule in order to determine the y-coordinate of point J in the rectangle fghj.
Step-by-step explanation:
The y-coordinate of point J in the rectangle fghj can be found by applying the given transformation rule. However, since the transformation rule is not provided in the question, I am unable to provide a specific answer in this case. Please provide the transformation rule so that I can assist you further.