Is this weighted mean and standard deviation correct?

[JorgeM]

TL;DR

I have to analize an small set of data(1000 points). But anyways I am not really sure if it is correct to use this one because this one refers to use an specific expression that I could not find anywhere.

The expression I have found is this one.
https://ibb.co/kqG24L3
I have been looking for information because I could not to realize what is the value that "alpha" has to have.

If any of you do know what this alpha value is supposed to represent or if you have seen it before I would be really grateful if you could help me.
Thanks
JorgeM

 

[Mark44]

In your image, where it gives the equation for the weights $w_i$, it also says that $\alpha$ is a constant, and there is a footnote (14). Possibly the footnote explains what the constant is, but the image doesn't show that part of the text.

 

[mathman]

The formulas (ignoring alpha) are general. The Definition of the weights in terms of alpha apprears to specific to the situation being discussed. What you need for the weights is determined by the nature of the data you have.

 

[JorgeM]

Yes, actually the footnote reffers to a GNU statistics library which instructions are not still available.
Can you please recommend me some bibliography to find out which is the best option (formula) that I may use to analize my data (The data is about stocks' prices)

 

[mathman]

I can't answer your question, since I don't what data you have. The weights should reflect relative importance of the items. That is for you to work out.