Re: probaility qns dse2013

Posted by kangkan on Mar 29, 2014; 8:07pm
URL: http://discussion-forum.276.s1.nabble.com/probaility-qns-dse2013-tp7585695p7585704.html

i..i think the first answer is 4/3*e^(-2)... for poisson E(X) as N tends to infinity is lamda...here it is 2.

Sp P(X=3)= e^-2.(2)^3/3! hence the answer..i am not 100%sure

Seond one 2/3.

Let A-event that both letters were from female

B- one letter from female and one from male

E-event that 1st letter recived was from female

hence now the porb is P(A/E)..apply bayes theorem and ans comes out as 2/3 :)