Rulɛt lab · Lab · Statistiks · 8 minit

Chi-skwɛ tɛst

Di standad tɛst fɔ “dɛn 37 kɔnt ya na wetin fɛr wil go mek?”

Shɔt ansa

χ² = Σ (wetin yu si − wetin yu fɔ ɛkspɛkt)² / wetin yu fɔ ɛkspɛkt, fɔ ɔl di 37 pɔkit. Kɔmpia am wit di chi-skwɛ distribyushɔn pan 36 digri fɔ fridɔm fɔ gɛt p-valyu.

statistik
Σ (O−E)²/E
digri fɔ fridɔm
36
kritikal valyu na 5%
51.0
kritikal valyu na 1%
58.6

Aw fɔ kalkul am

Di kɔnt we yu fɔ ɛkspɛkt fɔ ɛni pɔkitikwipmɛntPɔkitWan pan di 37 smɔl ples dɛn wit nɔmba pan di rotɔ. Dɛn kin kɔl am bak: slot, kɔp.Rid ɔl → na n/37. Fɔ ɛni pɔkit, tek di difrɛns bitwin wetin yu si ɛn wetin yu fɔ ɛkspɛkt, skwɛ am, ɛn dibay am wit wetin yu fɔ ɛkspɛkt; dɔn ad di 37 pat dɛn. Fɛr wil de gi valyu we de rawnd 36 pan avrej (di digri fɔ fridɔmlabDigri fɔ fridɔmDi nɔmba fɔ valyu dɛn we nɔ dipen pan wan ɔda insay wan statistik. Fɔ chi-skwɛ tɛst pan 37 pɔkit na 36, bikɔs ɔl di kawnt dɛn fɔ ad ɔp to di tɔtal.Rid ɔl →), wit standad diviyeshɔnmatematiksStandad diviyeshɔnDi skwɛ rut fɔ varians; di nɔmal distans bitwin wan rizɔlt ɛn di valyu we fɔ ɛkspɛkt.Rid ɔl → fɔ lɛk 8.5. Ɔp pas 51.0 na signifikant na di 5% lɛvel; ɔp pas 58.6 na 1%. Di Wil Bayas Analayza de kalkul di statistik ɛn di rayt rayt p-valyulabp-valyuDi prɔbabiliti fɔ si difrɛns we big lɛk di wan we yu si ɔ big pas am, if di wil bin fɛr.Rid ɔl → frɔm di regyularayz inkɔmplit gama fɔnkshɔn.

n spinwetin fɔ ɛkspɛkt fɔ ɛni pɔkitσ fɔ ɛni pɔkitpɔkit na +2σpɔkit na +3σ
370103.11619
1,000275.13742
3,7001009.9120130
10,00027016.2303319
37,0001,00031.21,0621,094
σ ≈ √(n·p·(1−p)) wit p = 1/37. Insay 1,000 spin, pɔkit we kam 37 tɛm nɔ spɛshal; wan we kam 42 tɛm fit fɔ sɛkɔn sampul.

Wan ɛgzampul we wi dɔn kalkul

1,000 spin. Tati-siks pɔkit kam bitwin 20 ɛn 34 tɛm; pɔkit 8 kam 41 tɛm. Wetin fɔ ɛkspɛkt na 27.03. Di pat fɔ pɔkit 8 in wan na (41 − 27.03)²/27.03 = 7.2. Se di ɔda 36 pat dɛn ad ɔp to 38 (nɔmal). χ² = 45.2 pan 36 df, p ≈ 0.14. I nɔ signifikant: fɛr wil de du dis wan tɛm pan sɛvin. Pɔkit 8 na sɔntin fɔ wach, nɔto sɔntin we yu dɔn fɛn, ɛn di ansa na ɔda wan tawzin spin.

Wetin di tɛst tek am se tru

Spin we nɔ dipen pan ɔda wanmatematiksSpin we nɔ dipen pan wan ɔdaƐni spin gɛt di sem prɔbabiliti, ilɛksɛf wetin dɔn apin bifo. Na dis ɛni kalkulɛshɔn na dis sayt bil pan.Rid ɔl →, ɛn kɔnt we yu fɔ ɛkspɛkt we pan ɔl 5 fɔ ɛni pɔkit. Dat min n ≥ 185 jɔs fɔ mek di tɛm wok, ɛn bɔku mɔ fɔ mek i gɛt yus. Fɔ miks spin frɔm difrɛn wil de brok di fɔs rul fɔ di tɛst in spirit (yu de tɛst miksɔ, nɔto wil). Ifɛkt frɔm di dila in yon sayn go brok am fɔ tru, ɛn i go mek χ² big ilɛk se nɔ pɔkit nɔ gɛt advantej pan di wil.

Di dila in yon we fɔ spinRulɛt spin we nɔ dipen pan ɔda wan

Pearson ɛn Monte Carlo

Karl Pearson bin pɔblish di tɛst na 1900, ɛn wan pan in fɔs ɛgzampul dɛn na 26,306 Monte Carlo rulɛt spin we dɛn bin rayt dɔŋ. I si se dɛn nɔ ikwal pas mɛzhɔ fɔ bi lɔk, ɛn i se “Monte Carlo rulɛt… nɔto gem fɔ chans”. Afta dat, ɔda raytman dɛn si se di jɔnalis dɛn we bin rayt di spin dɛn fɔ nyuspepa bin mek ɔp bɔku pan dɛn. Dat na in yon lɛsin bɔt usay data kɔmɔt.

Di tɛst ɛn di wil
1900

Pearson pɔblish di chi-skwɛ tɛst fɔ si if data fit di mɔdɛl, wit Monte Carlo spin as ɛgzampul.

di 1900 dɛn

Pipul de dawt di spin data; i luk lɛk se di wan dɛn we rayt am bin mek ɔp sɔm strik dɛn.

di 1920 dɛn

Fisher sɛt di digri fɔ fridɔm fayn; di 5% rul bigin fɔ tinap.

di 1940 dɛn–50 dɛn

Statistishan dɛn de yuz rulɛt spin as tɛksbuk data fɔ tɛst if tin ikwal.

di 1990 dɛn

Di García-Pelayo famili yuz di we wit rial data we dɛn rayt dɔŋ, ɛn dɛn win na Madrid.

tide

Kasino dɛn de rɔn di sem tɛst pan dɛn yon wil dɛn as nɔmal mentenans.

Pearson in tɛst na 1900 si se di Monte Carlo spin dɛn nɔ ikwal pas mɛzhɔ; di wan dɛn we bin rayt dɛn fɔ di nyuspepa bin mek ɔp bɔku pan dɛn.

Monte Carlo rulɛt

Wan rial tɛst: wil dɛn we de wok dɛnsɛf na Las Vegas

Bɔku tɛm, pleya dɛn de tink se wil we de wok insɛf de stia di bɔlikwipmɛntBɔlDi smɔl bɔl we dɛn trowe na di rod agens di rotɔ. Di nyu bɔl dɛn na ivorine ɔ Teflon, 18–21 mm.Rid ɔl → kɔmɔt frɔm big bɛt dɛn. Wan analisis na 2017 bin tɛst dis tink pan Interblock in wil dɛn wit dɔbul zirowilZiroDi wan grin pɔkit we nɔ ivin-mɔni, dɔzin ɔ kɔlɔm bɛt nɔ kɔba; na usay di kasino advantej kɔmɔt. Dɛn kin kɔl am bak: wan ziro, 0.Rid ɔl → na Las Vegas we nɔ gɛt dila, bay fɔ bɛt pan fayv nɔmba we de nia dɛnsɛf pan di wil: di kayn bɛt we pɔsin we de tɛm di wil kin mek. Insay 299 spin, di sɛkta win 29 tɛm, we dɛn bin fɔ ɛkspɛkt 39.3; fɛr wil de mek dis kayn shɔt lɛk 4% pan di tɛm. Di chi-skwɛ fɔ ɔl di 38 pɔkit na bin 45.29 pan 37 digri fɔ fridɔm: p = 16.5%. Sɛkɔn sampul fɔ 1,204 spin pan tri wil gi χ² = 34.79, p = 57%, ɛn nɔ sɛkta, ilɛk aw i big, nɔ bin signifikant. Di tu sampul togɛda, 1,503 spin, gi χ² = 41.75, p = 27%. Di jɔjmɛnt na se nɔ pruf nɔ de se di wil de stia. Di fɔs sampul in wan bin luk sɔspishɔs; na di sɛkɔn wan sɛtul am.

sampulspinχ²digri fɔ fridɔmp
fɔs29945.293716.5%
sɛkɔn, tri wil1,20434.793757%
di tu1,50341.753727%
Di nɔmba dɛn kɔmɔt frɔm da analisis de na 2017; ɛni p-valyu de fala in χ². Wil wit dɔbul ziro gɛt 38 pɔkit, so 37 digri fɔ fridɔm.

Pas chi-skwɛ

Fɔ wan pɔkit we yu de sɔspɛkt, binomial tɛst gɛt mɔ pawa. Fɔ wan pat pan di wil we yu de sɔspɛkt, yuz di sɛktawilSɛktaPɔkit dɛn we de fala wan ɔda na wan pat fɔ di wil, nɔto grup na di bɛt tebul.Rid ɔl → z-tɛst na di pej fɔ sɛkta analisis. Chi-skwɛ na di tɛst we de luk ɔltin: i de tɛl yu se sɔntin nɔ rayt, bɔt i nɔ de se wetin. Yuz am fɔs, dɔn luk.

Fɔ stɔdi di sɛkta dɛn

Fɔmula

χ² = Σᵢ (Oᵢ − Eᵢ)² / Eᵢ
Eᵢ = n / 37 · df = 36
kritikal valyu dɛn: 51.0 (5%) · 58.6 (1%)

Kwɛstyɔn dɛn

Wetin mek 36 digri fɔ fridɔm ɛn nɔto 37?

Di 37 kɔnt dɛn fɔ ad ɔp to n, so na 36 nɔmɔ fri fɔ chenj.

Wetin χ² wil we gɛt big bayas go sho?

Wil we wan pɔkit de kam 1/25 insay 10,000 spin go gi pɔkit pat fɔ lɛk 60 in wan; χ² lɛk 100, ɛn p go bi lɛk ziro.

A kin rɔn am pan 200 spin?

Pan pepa, yɛs, wit 5.4 fɔ ɛkspɛkt fɔ ɛni pɔkit. I nɔ go fɛn natin, pas if wan pɔkit pan di wil dɔn glu shɛt.

Smɔl jok fɔ ɛz di maynd

Ad ɔl di sɔprayz dɛn we yu dɔn skwɛ. Kɔmpia am wit 51.0.

Ad ɔl di sɔprayz dɛn we yu dɔn skwɛ. Kɔmpia am wit 51.0.

Usay wi gɛt am frɔm

  1. Pearson, K. “On the criterion that a given system of deviations from the probable…” Philosophical Magazine 50(302), 1900.
  2. Feller, W. An Introduction to Probability Theory and Its Applications, Vol. 1. Wiley, 3rd ed., 1968. Gambler’s ruin, chapta XIV.
  3. Wizard of Odds. “Organic Roulette Experiment.” Mach 2017; dɛn apdet am 3 Ɔgɔst 2026.
wi chɛk am 2026-09-28mɔdɛl: Yuropian, wan ziromɛtɔdɔlɔji ↗usay wi gɛt am frɔm ↗