CDF of average

lina2401

New Member
Hi all,
I hope that someone can help me with this! I have a list of values as below:
82.1134
84.5516
91.1851
65.6035
69.971
92.4706
79.1505
93.0844
92.9598

and I need to find the CDF of their average! how can calculate and present that in a chart? I do appreciate any help with this. Thanks in advance.
-Lina

Dason

You question doesn't really make sense. What do you mean by the CDF of their average? Their average is a single number...

lina2401

New Member
Maybe I should rewrite the question in a different way!
What would be the CDF of the above numbers?

Dason

Well do you know what a CDF is? What is the definition?

lina2401

New Member
All what I know is from the Wikipedia!! I tried to find some practical examples but I couldn't!

Mean Joe

TS Contributor
An important thing to know about the CDF (cumulative distribution function) is its definition...

Some basics:
the input to the CDF is a number. The output from the CDF is a number between 0 and 1.

If you see/say CDF(4.8)=0.25, then that means 25% of values from the distribution fall at/below 4.8.

seanw

New Member
Maybe I should rewrite the question in a different way!
What would be the CDF of the above numbers?
Hi lina2401,

It depends on what you mean by "the CDF." A CDF, as has been pointed out, is a function. You supply the value of x (a single observation from a distribution X), and the CDF gives you p(X<=x), i.e., the proportion of scores that are less than or equal to x, i.e., the probability of a single random observation from X being less than or equal to x. In that sense, "find the CDF" could simply mean "calculate p(X<=x) for each x".

If, on the other hand, by "find the CDF" you mean you want to identify what distribution these values come from, that's a much more complicated issue. For that, you'd need to consider the nature of the data, consider running some goodness-of-fit tests for different distributions, examine quantile reference plots, etc.

hlsmith

Less is more. Stay pure. Stay poor.
If it is for research why do you have to do this by hand? I would assume you could easily do it with Microsoft Excel or any other commonly available software.

rogojel

TS Contributor
hi,
this seems to be an application of the central limit theorem, no?