What is the difference between refference and indicator electrode​

The key difference between indicator electrode and reference electrode is that indicator electrode responds to changes in the activity of the analyte, whereas reference electrode does not respond to changes, and its response is stable.

Explanation:

93.2 ml + 3920 ml = 4013 ml total  

(93.2 ml) * (2.03 m) / (4013 ml) = 0.0471 m

the volume in in l of the diluted solution would be 0.0471 m.