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Post by wapentake on Oct 30, 2023 21:34:08 GMT
This stuff always did my head in at school,straightforward maths ok but when they came up with if a man walks a week in a fortnight how many apples in a pound of pears and I’d say sod off who cares.  I started walking 10 miles a day to get fit. By the end of the week I was 70 miles away and had to get a train home. With my luck if I’d done that on the seventh day the trains would go on strike  |
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Post by johnofgwent on Oct 31, 2023 15:04:50 GMT
Ok to start with us that ‘average’ the mean, median or mode
As someone skilled in the dark arts
Are we saying their age over the last decade was EXACTLY 55 ? Meaning they were born around the 30th June / 1st July ?
If they were then you have ten marks on a graph with 55 the median value and 50 and 60 at the edges which represent midsummer back and forward each year.
If their birthday were a different month then you just slide tbe C azis a bit
Simples
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Post by zanygame on Nov 1, 2023 7:36:36 GMT
Formula is quite simple (where X is age now) (X + (X-10))/2 =55 Solved by 2x-10=55*2 2x-10=110 2x=120 X=60 Median not mean. |
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Post by Baron von Lotsov on Nov 6, 2023 1:05:46 GMT
A throw away line in the cost of climate change thread by Dappy sent my mind off on a mathematical tangent. Dappy stated that over the last decade his average age was 55. So how old is Dappy now? My first thought was he must be 60 but... 51+52+53+54+55+56+57+58+59+60 = 555 which divided by 10 = 55.5 So I started the decade when Dappy was 50 but... 50+51+52+53+54+55+56+57+58+59 = 545 which divided by 10 = 54.5 So I thought Dappy must be 59.5 so then I would have to start the decade when he was 50.5 50.5+51.5+52.5+53.5+54.5+56.5+57.5+58.5+59.5 = 550 which divided by 10 = 55. Success at last but surely there's an easier way of solving the problem than my rather trial and error method? You are looking at the discrete average. What we do is make the interval tend to a limit of zero as we do for calculus to deal with continuous functions. Like in the last ten years you might check your age every minute and as you go to the limit it will be exactly midpoint, hence 60 is the right answer. |
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