Pulled from another thread

[SUNRAY]

Given that you are responding to quotes of two of my sentences (which probably have essentially 'opposite' answers) could you perhaps clarify what you are saying? In other words, are you happy with, say, "decreased by one third"?

Ah yes I see.
I'm happy with fractions and percentages and commonly flip back and forth between them.... Well apart from 'decimal fractions' with their plethora of definitions

Although I understand the usually intended meaning, the bit I don't like is n times smaller/cheaper etc.
Rather like some of the chestnuts we have on here such as: Plugtop, Live, Fusebox etc


This thread isn't an attack on anyone BTW

 

[SUNRAY]

Down a different track completely I had a funny a few weeks ago when we had a cold snap, is was something like 8°C one day and 2°C the next and someone said something like 4 times colder.

I picked up on it by converting to 45º & 35º and asked if they'd still say 4 times colder after the realisation I'd moved it to ºF a mutual friends schoolboy jumped on the band wagon and using ºK mentioned 275 and 281.

 

[JohnW2]

Ah yes I see. I'm happy with fractions and percentages and commonly flip back and forth between them.... Well apart from 'decimal fractions' with their plethora of definitions

"Decimal fractions" (as previously discussed) are, of course, simply 'percentages' with the decimal point moved!

Although I understand the usually intended meaning, the bit I don't like is n times smaller/cheaper etc.

Maybe because I'm dim, I'm still not totally clear about your position. I understand that you don't like "N times smaller/cheaper", but think you're happy with "N times larger/more expensive". Is that the case? What about "a quarter smaller/cheaper"?

Rather like some of the chestnuts we have on here such as: Plugtop, Live, Fusebox etc

Yes, of course, we all have our pet hates and irritations - but that's just human nature, and we all vary. "Plugtop" certainly irritates me (as does having to ask for a lamp to put in my lamp , but I'm personally not too affected by the other two!

 

[JohnW2]

Down a different track completely I had a funny a few weeks ago when we had a cold snap, is was something like 8°C one day and 2°C the next and someone said something like 4 times colder.

Yes, it is different - since you would similarly (hopefully!) not be happy with "4 times hotter" if the figures were reversed, although you have said written that you are, in general, happy with N times larger.

The point here is that proportions/ratios/percentages etc. can only be used with quantities/measurements which have what mathematically is described as a "ratio scale". That requires not only that points on the scale are equally spaced (an "interval scale") but also that there is a 'true zero'. As you go on to infer the absolute (Kelvin) temperature scale is a ratio one, but Celcius and Farenheit are only 'interval' scales, not 'ratio' ones.

 

[JohnW2]

I picked up on it by converting to 45º & 35º and asked if they'd still say 4 times colder after the realisation I'd moved it to ºF a mutual friends schoolboy jumped on the band wagon and using ºK mentioned 275 and 281.

I noticed a variant of this problem in a newspaper headline today ...

The headline was of the form "Mr A, aged 55, and Miss Y, nearly half his age". Half his age is 27.5, so this really shluld mean that she is a little under 27.5.

However, as one might expect from the fact that this was appearing as a 'headline', that is not what they meant. They actually meant that the difference between their ages is 'nearly' half of his age (i.e. she was a little over 27.5). She is, in fact, 29 !

 

[ericmark]

My wife has caught up with the maths of English now, she knows the answer to the question "You don't want another cup of coffee do you?" She answers, "I want a cup of coffee." No yes or no in the answer.

But we have so many errors. A boiler which does not boil the water, why are adverts for them not against the trade's description act?

I watch a lot of YouTube, and I see adverts for heating systems, and we see homes with an Energy performance certificate where gas tops electric, how? Electric is 100% or more if transferring energy rather than generating it. If called a Cost performance certificate, that would be a better name.

 

[ebee]

"One of the most common potential problems arises in relation to percentage changes/differences if people use the wrong wording. To say that the price of gas has "increased TO 150% over the past X years" is obviously very different from "increased BY 150% over the past X years" "

One of our local parties and their Election Rag a few years ago had an article about percentage increases etc and stated a few "facts".
Blimey none of them were any good at maths or arithmatic by a far bit off course of course - I did wonder if it was a deliberate polotics ploy or they were actually that stupid, did not me me a good feeling about whether to ever tust them again!

They were supposedly educated people!

Lots of folk make a common mistake if you give them a number then add 20% then subtract 20% and not ending up with the number started with, or, conversely the opposite start and finish by subtracting 20% etc etc.
Try to explain to them that the "Base Figure" is not constant in easy to understand language and there are still quite a few who don`t get it.

Mind you as a schoolboy someone tried to persuade that they had a bottle of spirit that was 110% alcohol.
I was mocked for quering it. Years later I looked at a bottle and it was degrees not percentage and years later I discovered alcohol was often quoted in degrees with 127 of them being 100% - If I remember correctly it was called something like the "Gaye Lussac" test.

Strange units - why 360 degrees in a circle ? etc etc

Mind you, around here, Half a pint of beer is often refered to as a gill.