Thread: probability mass function

In LOTTO 49, Michigan's lottery game, a player selects 6 integers out of the 49 positive integers. The state randomly selects 6 out of the first 49 integers. Cash prizes are given to a player who matches 4, 5 , or 6 integers. Let X equal the number of integers selected by a player that matches integers selected by the state.


Need help stating the p.m.f.

Don't know why but I just don't undertstand how to do this.

This seems to be a straight foward hypergeometric dist.
I assume we cannot pick a number twice, i.e., we are sampling without replacement.
If you replace the balls it's binomial.
In this case it's
P(X=x)= (6 choose x) (43 choose 6-x)/(49 choose 6)
x=0,1,2,...,6
You just want 4,5 and 6.