If I have three sets of numbers(adsbygoogle = window.adsbygoogle || []).push({});

A is numbers between 0 and 0.09

B is numbers between 0.091 and 0.011

C is numbers between 0.011 and 0.1

where the number of elements in A are say, 37, B are 16 and C are 178. So the three arrays have different numbers of points and different distances, plotting looks like this

How do I find the mean of all the points?

I was assigning weights based by multiplying the physical length of each section and number of points in each section, then getting the ordinary mean of each section, multiplying by this weight and then dividing by the sum of the weights, but I'm not sure if this is right

[tex]

\frac{w_A m_A + w_B m_B + w_C m_C}{w_A + w_B + w_C}

[/tex]

where

[tex]

w_A = l_A n_A

[/tex]

[tex]

l_A = 0.09-0

[/tex]

[tex]

n_A = 37

[/tex]

My way may be correct but it seems wrong? I've just guessed really. Any help greatly appreciated.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Weighted Mean: different sample size and variance

**Physics Forums | Science Articles, Homework Help, Discussion**