0

(12 + 18 + 5) / 3 (elements) = 11,67

and

(12 + 18) / 2 (elements) = 15

5 / 1 (element) = 5

(15 + 5) / 2 = 10

which one is more accurate? 11,67 or 10 ?

deldev
  • 179
  • You need some brackets. – Henry Mar 20 '15 at 21:31
  • Wow, this question suffers some serious format issues (without even mentioning the mathematical ambiguities). Start with writing down the title properly if you're expecting to be taken seriously. Then ask the question in a manner that will allow readers to understand what on earth it is that you're trying to ask. – barak manos Mar 20 '15 at 21:55
  • ok, sorry, is true! I correct it! – deldev Mar 23 '15 at 13:22

1 Answers1

2

The first time, each element is given a weight of $1$, whereas the second time, you consider the average of an element with the average of the two others: this is not at all the same thing, as the results indicate clearly.

Now, there is not a "more accurate" value - they are both accurate, but correspond to different quantities. If you want an average of $3$ elements with an equal weight, then your first formula is correct.

Demosthene
  • 5,420