maths
  • pne

141% more!

I saw an advert for a printer today that used the slogan “Was kostet 141% mehr Format?” (a bit difficult to translate, since that use of “Format” is not idiomatic for me even in German, but literally “What does 141% more format cost?”).

I only saw it from afar (enough to see the slogan and two pictures of printers), but I presume they were referring to printers that could print on A3 rather than A4 paper.

As you may know, the “A” series of paper sizes (defined in ISO 216 and commonly used in Europe, for example) have side ratios of 1:√2, which means that if you put two sheets next to each other along their long sides, they’ll be the same as the next bigger size of paper. So successive sizes have twice the surface area, and each side is √2 longer than the preceding size.

So “141% more format” is doubly wrong: even though it’s nonsensical to me at face value (I suppose, in printing there might be a jargon use of “format” that I don’t know…), the most obvious interpretation to me is area: but an A3 sheet of paper doesn’t have 141% more area than an A4 sheet: it has twice the area, or 100% more.

And even if they refer to side length: A3 isn’t 141% longer on each side, it’s 41% longer. Alternatively, it’s 141% of the length, but the ad referred to “141% more”.

I’m guessing the confusion arose from the fact that photocopiers in Europe often have predefined zoom values of 141%, 100%, and 71%, where 141% is useful for enlarging A5 to A4 or A4 to A3 (and 71% for the reverse)—so some poor innumerate person took the “141%” number relating A3 to A4 and made a slogan talking about “141% more”.

Which makes as much sense as telling someone who got a 2% pay raise that they are now earning “102% more money than before”.

Feh.

  • Current Mood
    annoyed annoyed

More percentage madness

Delaware governor Markell is proposing an 8% pay cut for all state employees.

In the comments, there's this gem from Moonrise:

"What about treating married vs single fairly. His plan does not do that. He wants to combine the two pays to say they are rich if their combined pay is $60, 000. That a $30, 000 a year job each. Two singles living together making the same about are considered under under paid. HUH. Another slap to married couples. A family of two state workers married are going to take a double hit on pay deduction, and lose their double share on healt benefit. Shouldn't it be double share it is two workers? Under Mackell this family is losing in the cost of medical plus takes a 16% pay cut. FAIR?"

not knowing math leads to making people scared

http://news.yahoo.com/s/afp/200711…

In this article on global warming, the writer makes the claim:

"The number of people affected by extreme natural disasters, meanwhile, has surged by almost 70 percent, from 174 million a year between 1985 to 1994, to 254 million people a year between 1995 to 2004, Oxfam said."

An increase of 70% from a base of 174 million should be 295.8 million. The writer did 174/254 to come up 70% (after a round off). It's actually a 42.6% increase, which is also pretty scary, but they are overstating the problem. However, in a few more years, we're prolly about that screwed.
flower

ancestry

So this happened some time ago, but I'm new to the community and I thought I should share.


After discussing my lineage with someone, an acquaintance, he commented that he too was part Irish. 1/8th Irish. He then commented that he was 1/3 Jewish.

I spent a great deal of time trying, as much as I could, to explain that this was impossible. He insisted (somehow) that he was in fact, exactly* 1/3 Jewish. I decided that whatever the case was, he was 0/3 good at math.

*added for clarity.

Further clarity:

I just re-read the community info, and it says maybe to provide explanation (I don't know if this counts as "college level"). So if anybody is wondering, no matter what part of your ancestry something is, it must be representable in least terms as k/2^n (for nonnegative integers k,n). The reason is this: at some level of your ancestry, presumably, there is a set of ancestors that are all "100%" something. There must be 2^n of them.* So you count up k of them to be something (eg Jewish), and that means you are k/2^n parts Jewish, by simply summing.

For example, if your father is 100% Italian and your mother is half Italian, half Chinese (with a 100% Italian parent, say her mother), then you skip up to that generation:

father's father: 100% Italian
father's mother: 100% Italian
mother's father: 100% Chinese
mother's mother: 100% Italian

There are 3 full-Italians, and 4 total. You are 3/4 Italian.

*regardless of if some are repeated - eg your grandfather is your mother's father and your father's father, he will essentially function as two distinct grandfathers in the summation, and will contribute two terms of 1/4.

You could also argue this inductively. Assume someone's parents are all k/2^n of anything (for various values of k,n). The child is simply the average of the two. So if the father is k/2^n of X, and the mother is p/2^q, then the child must be:

k/2^n + p/2^q = (k 2^q + p 2^n) / 2^(q+n)

While that is not in least terms, you can at best cancel out more twos. Note that this also accounts for cloning, in the sense that if the child is cloned, the inductive step involves no averaging and becomes trivial.

(no subject)

VH1 has these celebrity specials on TV all of the time. This one was from Rags to Riches talking about Naomi Watts and Nicole Kidman.

Text comes up showing Naomi Watts gets $5 million per picture.

The guy doing the voices informs us that Nicole Kidman gets "almost twice that" and text with $17.5 million comes up.