can someone look at this problem and tell me how they found the 45 please
P(X=2)=(10 2) (0.25)^2 (0.75)^8
45 (0.25)^2 (0.75)^8
=.2816

Question

can someone look at this problem and tell me how they found the 45 please
P(X=2)=(10  2) (0.25)^2 (0.75)^8
                45    (0.25)^2 (0.75)^8
=.2816

anonymous · Answer

@satellite73

anonymous · Answer

If 10 employed women are selected at random, what is the probability that exactly 2 have been married?
n=10, p=0.25

ganeshie8 · Answer

http://www.wolframalpha.com/input/?i=10+choose+2

ganeshie8 · Answer

$\large \binom{10}{2} =     ^{10}C_2 =      \dfrac{10!}{2!(10-2)!}$

ganeshie8 · Answer

its the number of ways of choosing 2 objects from a set of 10 objects.

ganeshie8 · Answer

The formula is :

$\large \binom{n}{r} =     ^{n}C_r =      \dfrac{n!}{r!(n-r)!}$