Question 1201085
<br>
"percent rate" does not have a clear meaning....<br>
Presumably "if a quantity is 4 times the size of its base" means a previous measurement of something was made and now the measurement is 4 times the previous one.  In that case...<br>
(1) The new measurement is 400% OF the old measurement;<br>
and<br>
(2) The new measurement represents a 300% INCREASE over the old measurement.<br>
So the answer to your question is PROBABLY either 300% or 400%... unless what you mean by "percent rate" is yet something different.<br>