Yes this is my homework, blah blah blah, but I can not figure out what the formula is to calculate the odds. I know that the chances of being 1/2 heads and 1/2 tails is about 25% and that 4 heads and 6 tails is about 20%. I am unable to show a formula that calculates these odds. I am a slow learner with algabra and need TLC in this area......Your thoughts and ideas will be appreciated..............................have a great day
2007-02-06 23:57:31 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
What does the ! stand for????
2007-02-07 01:51:56 · update #1
The formula for this is:
P(X=k) = (n chooses k) (p^k) ((1-p)^(n-k))
n is the total number of tosses
k is the number of times it lands on heads
p = .5 because that is the probability of a head
n chooses k is equal to: n!/((k!)(n-k)!)
So, if you are looking for the probability of 4 heads and 6 tails out of 10 tosses, you have:
P(X=4) = 210 * (.5^4) * (.5^6) = .205078 = 20.5%
I can clarify anything if you want me to.
2007-02-07 00:27:27 · answer #1 · answered by Nobody 3 · 2⤊ 0⤋
! means "factorial". That means you multiply that number by every integer between it and 1. For instance, 5! = 5*4*3*2*1 = 120.
2007-02-07 03:02:42 · answer #2 · answered by Amy F 5 · 1⤊ 0⤋
The probability of x "heads" in n tosses is nCx * (0.5)^n, where
nCx is the combinations formula = n!/[x!(n-x)!].
2007-02-07 00:36:54 · answer #3 · answered by Anonymous · 0⤊ 0⤋