Artificial Intelligence - Old Questions

9.  What do you mean by marginalization in probability distribution? Consider in Nepal, 51% of adults are males and rest are females. Consider one adult is randomly selected for a survey of drinking alcohol. It is found that 15% of males drink alcohol where as 2% of female drink alcohol. Now find the probability that the selected adult is a male.

Distribution over Y can be obtained by summing out all the other variables from any joint distribution containing Y. This process is called marginalization.

    P(Y) =ΣP(Y, Z)

Z --> No. of variables where Y seems to be true.