What's the difference between cdf and pdf in statistics?

Question

cdf stands for Cumulative Distribution Function 

pdf stands for Probability Distribution Function

 

Thanks

Answer 1

Hello, thank you for taking the time to post your question!

cdf is the cumulative distribution function

pdf is the probability density function

the main difference is in what is being measured … so the pdf tells you the probability at a specific point for continuous variables, whereas the cdf tells you cumulative probability of getting a value up to that point … so like the probability that a variable is less than or equal to a particular value

I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

P(x)=Probability density function  (Normalized such that integral from (-inf, inf)=1    [inf=infinity]

C(x)=Cumulative Distribution Function (C(x=-inf)=0, C(x=inf)=1)

 

∫P(x)dx (limits a,b) yields the probability that (a<x<b)

 

C(x) integrates the density function P(x) from -inf all the way to x to yield the cumulative probability from (-inf to x)

 

C(x) is tabulated for the Gaussian (Normal) distribution.  This makes it easy to find standard deviation probabilities merely by table-lookup without having to integrate.

Answer 3

Cdf -  Combination

 

  Pdf - Permutation.