1. In a way that agrees in amount, magnitude or degree
   "The profits were distributed proportionately among the shareholders";
   - pro rata
    
2. To a proportionate degree
   "your salary will rise proportionately to your workload";
   - proportionally
    
3. In a way that is in correspondence among the constituents of another entity
   "the height of this wall must be reduced proportionately to give the room pleasant dimensions"

Antonym: disproportionately