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random math question of the day
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| Photo_bot_2k1 |
Theres this thing I learned in statistics like a long time ago, about how even after you have like 10 male babies in a row the 11th still has a 50% chance of being male or female...
the thing i forgot was what this stupid pheonomenon/fallacy/thingermajiger was called!!!
i remeber it was a pretty neat name and its been bugging me forever!
time for your probability math nerds to come out and shine! |
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| kewlness |
phenomenon?? i think not
the reason the 11th baby is still 50% is because each event is INDEPENDANT of other events. For ex. just because my first kid was a male, won't make my second one more likely to be male or female.
I'll make up a law for this phenomenon
The probability law of independent events that don't affect the outcomes of other events.
phenomenal... |
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| Vigilante |
I can't recall the exact name of it, but i know exactly what you are talking about.
The same thing occurs with tossing a coin. There are onmly two possible outcomes, head and tails, and both have an equal probability of occurring. So if you toss the coin 10 times and you get ten head, the probability is still 50% that you will get tails on the next throw.
Think of if you then tossed it a million times. It would eventually approach 50/50 for heads and tails over time. |
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| joshyd |
i dont know any special name for it. but its just wat everyone said. each event is independent of other events.
with a coin, the odds are 50/50. if the coin is tossed 10 times then ud expect 5 heads and 5 tails.
theres no right or wrong |
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| ASOT100 |
| dude i hated Math 55 so much :whip: |
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| Nell |
| the whole difference being that you are not asking what is the probability of 11 of my babies being girls before you have them, you are only asking about 1 at a time. |
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| Streakfury |
Mutually exclusive??
The probability of having a girl is 1 in 2. The next time you have a baby, that probabilty wont change, it'll still be 1 in 2. The probability will change if you asked "what's the probability of having 11 girls in a row??" as opposed to just "...having 11 girls??".
:) |
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| Neuro'99 |
I have a similar example which may help/may not. If you pick two cards from a standard 52 card deck, without replacement, then the probability that the first card is a heart is the same as the probability that the second card is a heart, contrary to what your intuition may tell you. This is due to the Theorem of Total Probability, which deals with the probability of an event occurring (ie. the second card being a heart) given an event before it (the first card being a heart, or not a heart, both incompatible events, ie/ both cannot occur at the same time, but no other outcome can occur either).
I hope this helps, and thanks for sparking me into revision again lol ;) Cheers,
Mark |
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| AwakenedAddict |
| quote: | Originally posted by ASOT100
dude i hated Math 55 so much :whip: |
That's hilarious.. a friend of mine goes to berk and she used to complain about that class. I think she ended up 4th ranked in it tho ;) |
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| Floorfiller |
| quote: | Originally posted by Streakfury
Mutually exclusive??
The probability of having a girl is 1 in 2. The next time you have a baby, that probabilty wont change, it'll still be 1 in 2. The probability will change if you asked "what's the probability of having 11 girls in a row??" as opposed to just "...having 11 babies??".
:) |
mutually exclusive was the term that i learned... |
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| PVD & T[]C |
| quote: | Originally posted by Vigilante
The same thing occurs with tossing a coin. There are onmly two possible outcomes, head and tails, and both have an equal probability of occurring. So if you toss the coin 10 times and you get ten head, the probability is still 50% that you will get tails on the next throw.
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actually its not 50/50... see the tails half of the coin ways a little more than the heads half, so its more likely to get heads each time. if you flipped it 10,000 times you are going to get something like 4965 tails and 5035 heads. thats because the tails side is heavier, so it is more likely to end up on the bottom. its like 49.7/50.3 but yeah, i just felt like being an ass:D |
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| Streakfury |
| quote: | Originally posted by Floorfiller
mutually exclusive was the term that i learned... |
Yeah, it means that the two events are independant, and that the result of one wont affect the result of the other. So I guess I was right.
:D |
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