Do you mean two samples having same probability distribution? For what purphose do you want replace probability? Your question seems not bold enough for me to provide you with a good answer.
If I am reading you correctly, you may want to look into the Kolmogorv-Smirnov test. This can be used to test if two samples are from the same distribution, or if a sample is from a specific distribution. This test can be used to test fits for known distributions and if you find one that fits can substitute the sample with an actual distribution for further analysis. Is that what you're looking for?