Dantheman
Joined: Apr 21, 2015
• Posts: 53
November 24th, 2015 at 2:19:23 AM permalink
Quote: OnceDear

average number of times is 1/Probability which for a streak of 5 is about 36.7

Is this the probability of red 5 streak occuring?
Say im tracking both red and black, would i divide 36.7 by 2?
NokTang
Joined: Aug 15, 2011
• Posts: 1314
November 25th, 2015 at 2:35:04 AM permalink
Quote: Dantheman

Is this the probability of red 5 streak occuring?
Say im tracking both red and black, would i divide 36.7 by 2?

I'm not the math guy in this discussion, but it appears the one in apx. 36.7 refers to one(red) or the other(black) occurring five times in a row. Five spins in a row. We were unable to continue an intelligent discussion about it due to personal attacks being launched. A sad day actually....Cheers mate.
Dodsferd
Joined: Jun 10, 2015
• Posts: 375
November 25th, 2015 at 3:26:16 AM permalink
Quote: NokTang

I'm not the math guy in this discussion, but it appears the one in apx. 36.7 refers to one(red) or the other(black) occurring five times in a row. Five spins in a row. We were unable to continue an intelligent discussion about it due to personal attacks being launched. A sad day actually....Cheers mate.

An intelligent discussion and a discussion involving the emotional control regarding a game of probability are two different things.
This feeling is heavy, makes my body ache and I'm ready; To fall into the sky and I see now, the reason why. My heart is heavy, takes me to a place I can't breathe. Only then I know why I see the warning sign.
NokTang
Joined: Aug 15, 2011
• Posts: 1314
November 25th, 2015 at 3:29:21 PM permalink
Quote: Dodsferd

An intelligent discussion and a discussion involving the emotional control regarding a game of probability are two different things.

I'm not clear why you post that?

Having the emotional control to take your \$100.usd a day to live on, after laying apx 36 to 1 odds, seems intelligent enough to me. What have I got wrong? I think we all know you "can't" do this hour after hour, it takes "emotional control" to just do it once a day, have your prime rib dinner, do your laundry, watch the news, and sleep in the comfort of AC or heat, with running water etc..
mustangsally
Joined: Mar 29, 2011
• Posts: 2463
January 26th, 2018 at 11:53:52 PM permalink
Quote: Dantheman

I am wanting to find out the average number of spins it would take playing European roulette, if betting both black and red, to see a streak length of 2,3,4,5 etc

on average How many trials

easy to use formula for wait time until binomial run (streak) of successes

Now,
data for you
`18/37 0 Roulette(all calculated values here checked with simulations)run length:average number of spinsa=red2:6.2808641983:14.966220854:32.819453975:69.51776649			b=black2:6.2808641983:14.966220854:32.819453975:69.51776649c=red or black2:3.1404320993:7.4831104254:16.409726995:34.75888325c=a+b-dc=a/2 or b/2d=red and black2:9.4212962973:22.4493312754:49.229180955:92.05098036d=a+b-c`

not picking on any one (or two)

5 in a row for red
many say (18/37)^5=about 1 in 37 spins on average

that 37 is not spins
(Unless you count overlapping streaks and that is way too confusing to even attempt)
37 is the number of trials or attempts and each attempt is NOT 1 spin in length.

we need more for the average length of each trial
1+p+p^2+p^3+p^4,p=(18/37) = 3550231/1874161

(sure we can use 1 plus the sum of a geometric series
but this is different too)
1/(18/37)^5 * 3550231/1874161 = 131358547/1889568 =
69.52
Wolfram Alpha

in agreement with simple simulation results
`grouped dataitems:                  1000000   minimum value:                5.00first quartile:              23.00median:                      49.00third quartile:              95.00maximum value:              925.00mean value:                  69.48 <<<<<midrange:                   465.00range:                      920.00interquartile range:         72.00mean abs deviation:          48.35sample variance (n):       4301.07sample variance (n-1):     4301.07sample std dev (n):          65.58sample std dev (n-1):        65.58`

hope this helps out current and future visitors
averages are like apple eating
probability distributions are like a 10 course meal.
I am so hungry.

hope no errors
fun question!
Sally
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