Your working thus far is really good.
Now consider the CDF
You should find which is 'most' families.
hi guys.Can any one help me with this Q?
To control the population size and make a somewhat traditional population
happy at the same time, a government passes a law that requires couples to stop having
children once they have a son. Assuming that sons and daughters are equally likely,
the distribution of family size is geometric, with pdf given by
P(M = m) =1/2^m (Geometric distribution)
Interestingly, the average size of the family is 2, so the population size should stabilise. Since the standard deviation is radical 2, most families should have 5 or less children.
So how it got 5 children?