Re: probabilty

Posted by Sumit on Jun 01, 2013; 12:34pm
URL: http://discussion-forum.276.s1.nabble.com/probabilty-tp7581620p7581630.html

Sample space=(G,GB,GGB,GGGB......)...where P(G)=1/2, P(GB)=1/4 & P(GGB)=1/8 n so on
This is an GP whose some is=1

Now, A).P(family would have two children)=P(GB)=1/4.

Now Take X=no. of child a family have
So,X 1         2        3       4        5     so on
 P(x) 1/2    1/4    1/8   1/16      1/32 so on

For B) we need to find E(X)=1/2+2/4+3/8+4/16....=2.