Math Is Fun Forum

najon

Member

Registered: 2021-04-24

Posts: 1

HELP ! Calculate a score for Co2 emissions

I need to create a carbon footprint score. Meaning I have a bunch of Co2 footprints for different products, here’s a sample:

Product A: 235 kg Co2 eq.
Product B: 474 Kg Co2 eq
Product C: 389 kg Co2 eq
Product D: 434 kg Co2 eq

The score needs to be between 0 and 10 for each product according to their Co2 impact. I was thinking about using a normal distribution and assign a score according to their quartiles position if it makes sense. But I am not sure how to proceed.
These products are of the same category, so they are comparable.
I would really any help! Thanks

Bob

Administrator

Registered: 2010-06-20

Posts: 10,580

Re: HELP ! Calculate a score for Co2 emissions

Hi najon,

Welcome to the forum.

Before you can safely build a model such as a normal distribution you need much more data.  You say these are a sample so I'm assuming you've got lots more.  But are they normally distributed.  There are tests you can apply.  My first step would be to create a distribution graph. Is it symmetrical? Does it have a hump in the middle?

Once you know it's 'normal' you could divide into deciles (I think that's the right word for ten divisions).

Your model suggests that most products would score 5 or 6 , with 0 and 10 being quite rare. Is that right? I'd be a bit surprised if it is. If possible say more about the products and also say what the range, mean and standard deviation are.

Thinking some more , why not just divide the range into ten equal slots?

Later edit Actually I think that is what you're doing and the normal bit is interesting but not relevant to the score.  I'm assuming you want to publish the scores in order to encourage low footprints.  The EU have energy rating for white goods.  E is poor and A is best.  But then they had to introduce A+ for even better than A.  To avoid this problem it would be better to invert the scores so that low footprints gets the higher score.  Then if something comes along that is even better you can g to 11, then 12.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob