- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
re: Flip a coin 6 times. What are the odds for exactly 5 tails?
Posted on 8/31/23 at 6:52 am to GumboPot
Posted on 8/31/23 at 6:52 am to GumboPot
You didn't say whether the coin is fair. I'll assume it is.
Use a binomial distribution with trials = 6, successes = 5, and p=0.5. The probability is 0.094, and the odds are 0.094 / 0.906.
Use a binomial distribution with trials = 6, successes = 5, and p=0.5. The probability is 0.094, and the odds are 0.094 / 0.906.
Posted on 8/31/23 at 8:17 am to LordSaintly
I think the odds for getting any particular distribution you want to pick are always going to be the same: 0.5^6
This post was edited on 8/31/23 at 8:18 am
Posted on 8/31/23 at 8:28 am to GumboPot
Subtle "I have money" brag.
Posted on 8/31/23 at 8:39 am to Chucktown_Badger
quote:
I think the odds for getting any particular distribution you want to pick are always going to be the same: 0.5^6
Any single distribution, yes. But OP asked for exactly 5 tails. There are 6 ways to roll that:
quote:
HTTTTT
THTTTT
TTHTTT
TTTHTT
TTTTHT
TTTTTH
And 2^6=64 unique rolls
6/64=9.375% probability of exactly 5 tails
But he asked for the odds, so scenarios where it happens:scenarios where it doesn't.
(6/64)/(1-(6/64))
(6/64)/(58/64)
(6/58)=(3/29)
Like I said before, it's counterintuitive to write odds as a fraction in that way because it's too easily confused with probability. I'd write it as 29/3 or 29:3 if this was gambling, which is the same as 9.375% probability
ETA: the way I did 6/64 is the intuitive way, but for larger samples (say, flipping a coin 1000 times and wanting the probability of exactly 746 tails) you'd use the equation for binomial distribution. Unless you really like writing out permutations by hand
This post was edited on 8/31/23 at 8:53 am
Posted on 8/31/23 at 8:46 am to Ingeniero
Yup, it just struck me and I was coming back in here to edit my post
Posted on 8/31/23 at 9:19 am to Ingeniero
quote:
But he asked for the odds
That was on purpose but not as a gotcha. Until my son came to me with this problem from his LSU probability course I've always conflated probability with odds like most people. The two concepts are different as you have outlined.
Posted on 8/31/23 at 9:24 am to 98eagle
quote:
Whatever the odds are, they are much higher than going to Vegas and consecutively betting 6 times on "Red" on the roulette wheel and winning 5 times. Amazingly the house has much greater odds of beating you 5 out of 6 times on a basically 50/50 bet. It's really uncanny.
It isn't a 50/50 bet. There are four green squares.
Posted on 8/31/23 at 9:49 am to Chucktown_Badger
quote:
0.5^6
That's the probability of six heads in a row which isn't what the OP needs.
Popular
Back to top
Follow TigerDroppings for LSU Football News