The missing word in the sentence
“Controlling function finds out how far __________ deviates from standards”
is “actual performance.”

So, the complete sentence is:
“Controlling function finds out how far actual performance deviates from standards.”

In management, the controlling function involves:

  • Setting performance standards.
  • Measuring actual performance.
  • Comparing actual performance with standards to identify deviations.
  • Analyzing deviations and taking corrective action.

Here, the key role of controlling is precisely to measure the gap between the actual performance and the predetermined standards and then trigger corrective measures if needed.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.