Final answer:
To verify the accuracy of the glide slope at KGEG's ILS RWY 3 when crossing OLAKE, one must refer to the specific approach chart for the correct altitude, which is not provided in the question.
Step-by-step explanation:
When approaching to land at KGEG on the ILS RWY 3, and crossing the OLAKE waypoint, the altitude check is a standardized procedure to ensure that you are on the correct glide path. The altitudes provided are associated with specific waypoints along the approach path that help pilots verify they are descending correctly on the Instrument Landing System (ILS) glide slope. According to the approach chart for KGEG ILS RWY 3, when crossing OLAKE, you would expect to be at the glide slope intercept altitude which is typically noted in the approach procedures. The correct altitude to verify the accuracy of the glide slope when crossing OLAKE would be the one specified in the approach chart for that airport.