Is strength of an acid proportional to concentration or dilution?
Is strength of an acid proportional to concentration or dilution?
  


This is an interesting question. It is sort of like being asked "What is your size?". If you are buying shoes then size means one thing, yet it is something different if you are buying pants. 

So there are two different "strengths." 

Strength can mean how much acid is present. So per unit volume of solution, a solution with 50% concentration has half the strength of the 100% concentration.

Strength can also mean how acidic, in terms of pH, would a specific solution be if the acid concentration were kept constant. In this sense hydrochloric acid is a stronger acid that acetic acid. 

So the gist of your problem is that you're trying to draw a comparison between two different uses of the word strength when such a comparison is pointless.