Math question
if you know basic math, please help
I’m figuring out percentage changes… i know the basic formula is new-old/old*100… so for example, if our student population in 2006 was 5863 and in 2007 it was 6169, the increase is 5.2%. fine, easy enough… but what if the base number is a zero? b/c you can’t divide by zero and i’m having a total brain fart as to how to figure this out… so for example, in 2006, the math program had zero students but in 2007 it had 3. is that an increase of 300%? it just seems so drastic.
thanks!
Comments
Phew… well it would be an increase of 300% if there was 1 single student in 2007.
Any percent of 0 is 0. If you’re taking the percentage of some past value, would it ever be zero? I mean, would you call it a math program if it had no students in it?
If it started from zero, then there was no math program, and I don’t belive you can measure it by percent, since percentage refers to change from an original number.
I work in television btw, and aside from bar tabs, thats the first time I’ve done much with numbers in a long time, so, maybe not.
He beat me.
It hurts me more than it hurts you.
but it seems so misleading to say the math program increased by 0% when actually it increased by a lot in real numbers (i mean, comparatively of course). i’m convinced there is a way… maybe we can come up with a new mathematical formula and we’ll win a nobel prize or something.
So someone started a math program and didn’t have any students the first year?!?!
I would just report: “After a shitty first year, the school decided to actually include math topics in their math program. In year 2, they finally got students, 3 to be exact.”
The long short of it, Dawn, is that you can’t say something increased by a percentage from zero. To say something increased by n% is to give a value of the increase based on the original number. However, if the original number is nil, you cannot take a percentage of it.
Thus, your answer, technically, is “undefined.” There is no way to do what you’re trying to do.
E.g., 306 is the difference between 6169 and 5863 in your example. 306 is 5.2% of 5853, so you can say that pop. increased by 5.2%.
However, with the math class, 3 is the difference between 3 students and 0 students. 3 is not ANY percent of zero, because you cannot slice nothing up into percentages. Thus, you cannot talk about a percentage increase from nothing.
that makes me sad john… but then i re-read paris’s suggestion and i laughed.
Why does talking about math make me drop my contractions? Insta-douche!
You can get creative if you want to though. Technically, the math program officially began when the 1st person signed up for it (assuming everyone didn’t sign up at the same exact time). So, if you want to be a smart-ass, you can say that the program experienced a 300% increase in whatever short amount of time elapsed between the first person signing up and the third person signing up.
Realistically, though, if you’re writing some sort of technical report, it would be incorrect to discuss any sort of growth between what you are describing as the 1st year and the 2nd year, since your program didn’t really exist in the first year. Think of it as a bar chart, or any other graphical tool. You’d only have one set of values and nothing to compare them to, so they are basically menaingless.
Is there a reason why you’re worried about expressing this as a percentage? Do you need to impress someone with numbers or fancy pictures or something (honest question, I have to do the same all the time).
yes, i’m tracking student populations in all our programs (i work at a community college) since 2002, with specific columns for 1-year (06-07), 3 year (04-07) and 5 year (02-07) percentage changes in the population of the program. it’s a big old chart, and actually b/c of this silly mathematical snag, a chart with a lot of holes.
however, i still maintain it’s more logical to address that having 0 zero students in year x compared to 3 students in year y is an increase (fine not in percentages but that’s kind of the standard medium for this type of analysis)… but we have to let the math do the talking. So, my compromise is a bold note under the chart that points to this phenomenon.
Paris said:Phew… well it would be an increase of 300% if there was 1 single student in 2007.
I think you’re wrong here, Paris. If the 2008 Math program had 3 students, and the 2007 Math program had 1 student, wouldn’t it be an increase of 200%?
Yeah, 3 is 300% of 1, but it’s a 200% increase, sure sure. Whateeeeever.
I’m the new math champ!!!!
Hutch: make me a quick little asterisks or something that denotes I’m the reigning math champ. Put it by my username.