The two sample problem Two independent random sample are observed xa and xb drawn from possibly different probability density functions: Fgxa={x,1,…,X,n} Fbxb={xb,1,…,b,m} Definition The null hypothesis Hto assumes that there is no difference in between the density function Fa=Fb. R.Dahyot (TCD) 453 Moder statistical methods 20057/22The two sample problem Two independent random sample are observed xa and xb drawn from possibly different probability density functions: Fa xa = {xa,1, · · · , xa,n} Fb xb = {xb,1, · · · , xb,m} Definition The null hypothesis H0 assumes that there is no difference in between the density function Fa = Fb. R. Dahyot (TCD) 453 Modern statistical methods 2005 7 / 22