Wizard
Joined: Oct 14, 2009
• Posts: 23278
January 8th, 2016 at 3:39:06 PM permalink
Math time! Assume that Alan's memory is such that if an event happens to him, he will remember it accurately 99% of the time. Also assume that if something never happened to him, there is a 1% chance he will incorrectly say that it did. He has witnessed 20,000 dice rolls in his lifetime. He claims that at one time he witnessed 18 consecutive yos. What is the probability this is a true statement?

You may use the approximation of the probability of 18 consecutive yos in 20,000 totals rolls of 20000/(18^18). An exact form of that probability would be rather complicated to work out.
It's not whether you win or lose; it's whether or not you had a good bet.
RonC
Joined: Jan 18, 2010
• Posts: 4874
January 8th, 2016 at 3:43:22 PM permalink
Quote: Wizard

Math time! Assume that Alan's memory is such that 99% of events happened as he claims. He has witnessed 20,000 dice rolls in his lifetime. He claims that at one time he witnessed 18 consecutive yos. What is the probability this is a true statement?

I'll be interested in seeing if the mathletes can solve this problem without personal insults now that they have the protection of Alan not being a member in good standing. I think it is a good problem to work and I don't know if he saw it or not, but too many seem to think that it is IMPOSSIBLE rather than highly IMPROBABLE. Toss in an insult and there goes another decent member.
Canyonero
Joined: Nov 19, 2012
• Posts: 509
January 8th, 2016 at 3:56:53 PM permalink
Quote: RonC

too many seem to think that it is IMPOSSIBLE rather than highly IMPROBABLE. Toss in an insult and there goes another decent member.

But the numbers don't say "highly improbable". The numbers say "It didn't happen."

If Alan were on trial for murder, and the probability that he were innocent were 1000x higher than 18 yos in a row, he would be sentenced to death in a heartbeat. Guilty way beyond reasonable doubt.
RS
Joined: Feb 11, 2014
• Posts: 8623
January 8th, 2016 at 4:03:06 PM permalink
Unfortunately, I believe the "member not in good standing" does not apply to those who have self-banned themselves. Perhaps we still can't freely insult Alan, but he is in red now....and I think for a minimum of 1 year.

I wish 1BB was still here. I wonder how many people he would have reported for personal insults....oh, the world may never know!
Wizard
Joined: Oct 14, 2009
• Posts: 23278
January 8th, 2016 at 4:15:59 PM permalink
Quote: RS

Unfortunately, I believe the "member not in good standing" does not apply to those who have self-banned themselves. Perhaps we still can't freely insult Alan, but he is in red now....and I think for a minimum of 1 year.

We've never set a firm policy on this, but Alan asked that we delete his account, which we can't do, but I interpret that as a wish to give up his right to return and insult protection. So, he can be assumed to be a non-member. However, let's still be gentlemen about it. Alan may not be a probability wiz and his memory may not be perfect but he seemed like a very decent nice guy to me.
It's not whether you win or lose; it's whether or not you had a good bet.
Joined: Apr 4, 2012
• Posts: 6506
January 8th, 2016 at 4:25:03 PM permalink
Quote: Canyonero

But the numbers don't say "highly improbable". The numbers say "It didn't happen."

If Alan were on trial for murder, and the probability that he were innocent were 1000x higher than 18 yos in a row, he would be sentenced to death in a heartbeat. Guilty way beyond reasonable doubt.

hmmmmmm ever hear of the OJ verdict?

If Alan stated a 13 was rolled then yes "it didn't happen" but an 11 coming up 18 hands in a row is a mathematical probability

each roll of the dice is independent from the last roll
OnceDear
Joined: Jun 1, 2014
• Posts: 5528
January 8th, 2016 at 4:38:01 PM permalink
Quote: SOOPOO

He did not see 18 yo's in a row. Is there any forum member who actually believes he did?

I believe that Alan possibly believes that he saw 18 yos in a row.

He didn't actually happen, but that won't stop him stubbornly asserting that he did.

He has invested too much of himself to that absurd belief and he will be damned if he'll ever back down. If he's any concept of the enormous improbability of his assertion, and of course if he had an ounce of humility, he would have thought long and hard about whether he might just need to question his own reliability as a witness. But probability and maths are not his strong suit ( by his own admission). IMHO humility isn't his strong suit either. (not to mention engineering, ballistics, English comprehension or logical thought )

Alan makes a fool of himself by not acknowleging that he has spouted a completely incredible nonsense. For anyone who is daft enough inclined to frequent Alan's own forum, he tacitly admits that his motivation for spouting such nonesense here was as much about winding up us 'mathletes' as anything else.

I won't miss his contribution here.
Last edited by: OnceDear on Jan 8, 2016
Beware. The earth is NOT flat. Hit and run is not a winning strategy: Pressing into trends IS not a winning strategy: Progressives are not a winning strategy: Don't Buy It! .Don't even take it for free.
RS
Joined: Feb 11, 2014
• Posts: 8623
January 8th, 2016 at 4:43:39 PM permalink
Quote: Wizard

We've never set a firm policy on this, but Alan asked that we delete his account, which we can't do, but I interpret that as a wish to give up his right to return and insult protection. So, he can be assumed to be a non-member. However, let's still be gentlemen about it. Alan may not be a probability wiz and his memory may not be perfect but he seemed like a very decent nice guy to me.

I guess we all have different opinions. I wouldn't consider someone who posted here strictly to cause a rouse as a decent nor nice person, re: 2-dice-puzzle but particularly 18-yos-in-a-row. It's not that he's bad at probability or math, it's that he chooses to defy (or rather, refuse to accept) math and probability, attacking the "mathletes". Stubborn, I suppose, is the best word to describe him.
OnceDear
Joined: Jun 1, 2014
• Posts: 5528
January 8th, 2016 at 4:46:49 PM permalink
Quote: RS

I Stubborn, I suppose, is the best word to describe him.

Didn't somebody once suggest stubtuse?
\$:o)
Beware. The earth is NOT flat. Hit and run is not a winning strategy: Pressing into trends IS not a winning strategy: Progressives are not a winning strategy: Don't Buy It! .Don't even take it for free.
Wizard