I think the answer is yes you can because they are both different things.
What I mean by that is that the United Stated as .151% of its people with hearing problems, and .093% with vision problems. So really adding them together just mixes it saying that .244% of people in the united states have either a vision or a hearing problem.
It doesn’t make it any more or any less people by adding them together. Therefore it’s not any more or any less probable to pick one or the other.
Hopes this helps.
A non-negative root of a number is called Square Root
