Both, but they have different meanings; one is relative, the other absolute.
If something is measured at 70% of something else, and increases by 10%, it goes up to 77% - an increase of 10% relative to the original reading.
If something is measured at 70% of something else, and increases 10% it goes up to 80% - an absolute increase of 10%.
Public speakers often confuse these, some would say deliberately. I take a more generous view: I think they just don't understand the difference, and say whichever sounds best.
b
Are you certain about that? I have never heard that distinction in medicine.
If I intended your second meaning, I would say increased 10 precentage points.
Yep, people often say "per cent" when they mean "percentage points". But in the domain of mathematics, that is an error -- and potentially a very serious one.PS - e pur si muove: I'm sure I've heard bosses say things like: 'The figures are 70% of last year. We need to increase those 10% this year' - and they didn't mean 'to 77%'.
Yep, people often say "per cent" when they mean "percentage points". But in the domain of mathematics, that is an error -- and potentially a very serious one.
:up: Thanks for the clarification.
b
PS
In another string, Mike said '... in our attempt to create interesting and complex grammar rules to explain this error, I think we forget how easy it is to pick up the language mistakes of others.' I suspect I was creating an interesting and complex grammar rule to justify a simple mistake.
So are we all in agreement that, considering a base of 70%, an increase of 10% and increased by 10% both produce 77%?
OK OK OK :lol: I'm eating humble pie! There - satisfied? ;-) It does :up:
b
Thanks, teachers!
I also checked the dictionary, which confirms that it should be "increase (something) BY something", eg. Food prices increased by 10% in less than a year.
I am clear about it now.
Thanks again.