Ntxiv thiab ntau qhov tshwm sim: piv txwv ntawm kev daws teeb meem thiab kev xav

Cov txheej txheem:

Ntxiv thiab ntau qhov tshwm sim: piv txwv ntawm kev daws teeb meem thiab kev xav
Ntxiv thiab ntau qhov tshwm sim: piv txwv ntawm kev daws teeb meem thiab kev xav
Anonim

Kev kawm txoj kev xav ntawm qhov tshwm sim pib nrog kev daws teeb meem ntawm kev sib ntxiv thiab kev sib npaug ntawm qhov tshwm sim. Nws yog ib qho tsim nyog hais tam sim ntawd tias thaum paub txog qhov kev paub no, tus tub ntxhais kawm yuav ntsib teeb meem: yog tias cov txheej txheem ntawm lub cev lossis tshuaj muaj peev xwm sawv cev rau qhov pom thiab nkag siab txog qhov pom, ces qib ntawm kev ua lej ntawm kev ua lej yog siab heev, thiab kev nkag siab ntawm no tsuas yog los nrog. kev paub.

Txawm li cas los xij, qhov kev ua si tsim nyog rau lub tswm ciab, vim tias cov qauv - ob qho tib si suav nrog hauv kab lus no thiab ntau qhov nyuaj - tau siv txhua qhov chaw niaj hnub no thiab tej zaum yuav muaj txiaj ntsig zoo hauv kev ua haujlwm.

Keeb Kwm

Oddly txaus, lub impetus rau txoj kev loj hlob ntawm cov zauv seem no yog … twv txiaj. Tseeb, tsuav, npib tos, poker, roulette yog cov piv txwv zoo uas siv qhov sib ntxiv thiab sib npaug ntawm qhov tshwm sim. Ntawm qhov piv txwv ntawm cov dej num hauv ib phau ntawv nyeem, qhov no tuaj yeem pom meej. Cov neeg tau txaus siab kawm yuav ua li cas nce lawv txoj hauv kev yeej, thiab kuv yuav tsum hais, qee qhov ua tiav hauv qhov no.

sib ntxiv thiab sib npaug ntawm qhov yuav tshwm sim
sib ntxiv thiab sib npaug ntawm qhov yuav tshwm sim

Piv txwv li, twb nyob rau tiam 21st, ib tug neeg, nws lub npe peb yuav tsis qhia,siv qhov kev paub no tau sau ntau pua xyoo los ua "tshuaj" lub twv txiaj yuam pov, yeej ntau kaum lab nyiaj daus las ntawm roulette.

Txawm li cas los xij, txawm hais tias muaj kev txaus siab ntau ntxiv hauv qhov kev kawm, nws tsis yog txog rau xyoo pua 20th uas tau tsim cov qauv theoretical uas ua rau "theorver" ua ib feem ntawm kev ua lej. Niaj hnub no, yuav luag txhua qhov kev tshawb fawb, koj tuaj yeem nrhiav kev suav nrog cov txheej txheem probabilistic.

Applicability

Ib qho tseem ceeb thaum siv cov qauv ntawm qhov sib ntxiv thiab qhov sib npaug ntawm qhov yuav tshwm sim, qhov tshwm sim ntawm qhov tshwm sim yog qhov txaus siab ntawm lub hauv paus txwv theorem. Txwv tsis pub, txawm hais tias nws yuav tsis paub los ntawm tus menyuam kawm ntawv, txhua qhov kev suav, txawm tias lawv yuav zoo li cas, yuav tsis raug.

Yog lawm, cov neeg kawm uas muaj kev txhawb siab siab heev raug ntxias kom siv cov kev paub tshiab ntawm txhua lub sijhawm. Tab sis nyob rau hauv cov ntaub ntawv no, ib tug yuav tsum tau qeeb me ntsis thiab nruj me ntsis piav qhia txog qhov kev siv tau.

Zoo qhov kev xav tau cuam tshuam nrog cov xwm txheej random, uas nyob rau hauv cov ntsiab lus empirical yog cov txiaj ntsig ntawm kev sim: peb tuaj yeem dov rau 6-sided tuag, kos ib daim npav los ntawm lub lawj, kwv yees tus naj npawb ntawm cov khoom puas hauv ib pawg. Txawm li cas los xij, hauv qee cov lus nug nws yog categorically tsis yooj yim sua kom siv cov qauv los ntawm ntu no ntawm kev ua lej. Peb yuav tham txog cov yam ntxwv ntawm kev txiav txim siab qhov tshwm sim ntawm qhov tshwm sim, theorems ntawm kev sib ntxiv thiab kev sib faib ntawm cov xwm txheej hauv qhov kawg ntawm tsab xov xwm, tab sis tam sim no cia peb tig mus rau cov piv txwv.

Basic concepts

Ib qho xwm txheej random txhais tau tias qee qhov txheej txheem lossis qhov tshwm sim uas yuav tshwm sim lossis tsis tshwm simraws li qhov tshwm sim ntawm qhov kev sim. Piv txwv li, peb pov lub qhaub cij - nws tuaj yeem poob butter lossis butter. Ob qho kev tshwm sim yuav tshwm sim, thiab peb tsis paub ua ntej uas lawv yuav tshwm sim.

Qhov tshwm sim ntawm qhov kev tshwm sim ntawm qhov theorem ntawm qhov sib ntxiv thiab sib npaug ntawm cov xwm txheej
Qhov tshwm sim ntawm qhov kev tshwm sim ntawm qhov theorem ntawm qhov sib ntxiv thiab sib npaug ntawm cov xwm txheej

Thaum kawm ntxiv thiab sib npaug ntawm qhov yuav tshwm sim, peb xav tau ob lub ntsiab lus ntxiv.

Cov xwm txheej sib koom yog cov xwm txheej, qhov tshwm sim ntawm ib qho uas tsis suav nrog qhov tshwm sim ntawm lwm qhov. Wb hais tias ob tug neeg tua ntawm ib lub hom phiaj tib lub sijhawm. Yog hais tias ib tug ntawm lawv tua ib tug zoo txhaj tshuaj, nws yuav tsis cuam tshuam rau lwm tus lub peev xwm ntaus los yog nco.

Kev tsis sib haum yuav yog cov xwm txheej zoo li no, qhov tshwm sim ntawm ib txhij ua tsis tau. Piv txwv li, tsuas yog rub ib lub pob tawm ntawm lub thawv, koj tsis tuaj yeem tau txais ob qho tib si xiav thiab liab ib zaug.

Kev tsim qauv

Lub tswv yim ntawm qhov yuav tshwm sim yog txhais los ntawm Latin tsab ntawv P. Tom ntej no hauv cov kab ke yog cov lus sib cav uas qhia txog qee qhov xwm txheej.

Nyob hauv cov qauv ntawm qhov sib ntxiv theorem, qhov tshwm sim ntawm qhov tshwm sim, kev sib tshooj theorem, koj yuav pom cov kab lus hauv cov kab ke, piv txwv li: A + B, AB lossis A|B. Lawv yuav muab xam rau hauv ntau txoj kev, tam sim no peb yuav tig mus rau lawv.

Ntxiv

Cia peb xav txog cov xwm txheej uas siv cov qauv sib ntxiv thiab sib npaug.

Rau cov xwm txheej tsis sib xws, cov qauv sib ntxiv uas yooj yim tshaj plaws yog qhov cuam tshuam: qhov tshwm sim ntawm ib qho ntawm qhov tshwm sim random yuav sib npaug rau qhov sib npaug ntawm qhov tshwm sim ntawm txhua qhov tshwm sim.

teeb meem sib ntxiv thiab sib npaugQhov yuav tshwm sim
teeb meem sib ntxiv thiab sib npaugQhov yuav tshwm sim

xav tias muaj ib lub thawv nrog 2 xiav, 3 liab thiab 5 lub zais pa daj. Muaj 10 yam khoom hauv tag nrho hauv lub thawv. Qhov feem pua ntawm qhov tseeb ntawm nqe lus uas peb yuav kos lub pob xiav lossis liab yog dab tsi? Nws yuav muab sib npaug rau 2/10 + 3/10, i.e. tsib caug feem pua.

Thaum cov xwm txheej tsis sib xws, cov qauv yuav nyuaj dua, txij li lub sijhawm ntxiv ntxiv. Peb yuav rov qab mus rau nws hauv ib kab lus, tom qab xav txog ib qho ntxiv.

Multiplication

Ntxiv thiab ntau qhov tshwm sim ntawm cov xwm txheej ywj pheej yog siv nyob rau hauv ntau qhov sib txawv. Yog tias, raws li qhov xwm txheej ntawm qhov kev sim, peb txaus siab rau ib qho ntawm ob qhov txiaj ntsig tau, peb yuav suav cov lej; Yog tias peb xav tau ob qho txiaj ntsig ib qho tom qab lwm qhov, peb yuav siv cov qauv sib txawv.

Rov qab mus rau qhov piv txwv ntawm ntu dhau los, peb xav kos lub pob xiav ua ntej thiab tom qab ntawd liab. Thawj tus lej peb paub yog 2/10. Yuav ua li cas ntxiv? Muaj 9 lub npas tshuav, tseem muaj tib tus lej liab - peb daim. Raws li kev suav, koj tau 3/9 lossis 1/3. Tab sis yuav ua li cas nrog ob tus lej tam sim no? Lo lus teb raug yog muab faib kom tau 2/30.

Joint Events

Tam sim no peb tuaj yeem rov mus xyuas cov lej lej rau kev sib koom ua ke. Vim li cas peb thiaj li tawm ntawm lub ncauj lus? Kawm seb yuav ua li cas thiaj muaj ntau ntxiv. Tam sim no qhov kev paub no yuav los ua ke.

sib ntxiv thiab sib npaug ntawm qhov yuav tshwm sim conditional probability
sib ntxiv thiab sib npaug ntawm qhov yuav tshwm sim conditional probability

Peb twb paub tias thawj ob nqe lus yuav ua li cas (zoo ib yam li hauv cov qauv sib ntxiv tau txiav txim siab ua ntej), tam sim no peb yuav tsum tau rho tawmcov khoom ntawm qhov tshwm sim uas peb nyuam qhuav kawm los suav. Kom paub meej, peb sau cov qauv: P (A + B) u003d P (A) + P (B) - P (AB). Nws hloov tawm tias ob qho tib si sib ntxiv thiab sib npaug ntawm qhov tshwm sim yog siv hauv ib qho kev qhia.

Thov hais tias peb yuav tsum daws ob qho teeb meem kom tau txais credit. Peb tuaj yeem daws qhov ua ntej nrog qhov tshwm sim ntawm 0.3, thiab qhov thib ob - 0.6. Kev daws: 0.3 + 0.6 - 0.18=0.72. Nco ntsoov tias tsuas yog sau cov lej ntawm no yuav tsis txaus.

Txoj Kev Muaj Peev Xwm Txheej

Thaum kawg, muaj lub tswv yim ntawm qhov xwm txheej tshwm sim, cov lus sib cav uas tau qhia hauv cov kab ke thiab sib cais los ntawm kab ntsug. Qhov nkag P(A|B) nyeem raws li hauv qab no: "qhov tshwm sim ntawm qhov tshwm sim A muab qhov xwm txheej B".

Cia saib ib qho piv txwv: ib tug phooj ywg muab rau koj ib co ntaus ntawv, cia nws ua ib tug xov tooj. Nws tuaj yeem tawg (20%) lossis zoo (80%). Koj tuaj yeem kho txhua yam khoom uas poob rau hauv koj txhais tes nrog qhov tshwm sim ntawm 0.4 lossis koj tsis tuaj yeem ua nws (0.6). Thaum kawg, yog tias lub cuab yeej ua haujlwm, koj tuaj yeem ncav cuag tus neeg zoo nrog qhov tshwm sim ntawm 0.7.

Nws yooj yim pom tias qhov xwm txheej tshwm sim ua haujlwm li cas hauv qhov no: koj tsis tuaj yeem nkag mus rau tus neeg yog lub xov tooj tawg, thiab yog tias nws zoo, koj tsis tas yuav kho nws. Yog li, txhawm rau kom tau txais cov txiaj ntsig ntawm "theem thib ob", koj yuav tsum paub tias qhov xwm txheej twg raug tua rau thawj zaug.

Kev suav

Cia peb xav txog cov piv txwv ntawm kev daws teeb meem ntawm kev sib ntxiv thiab kev sib npaug ntawm qhov tshwm sim, siv cov ntaub ntawv los ntawm kab lus dhau los.

Ua ntej, cia peb nrhiav qhov tshwm sim uas kojkho cov cuab yeej muab rau koj. Txhawm rau ua qhov no, thawj zaug, nws yuav tsum ua yuam kev, thiab qhov thib ob, koj yuav tsum tiv nrog kev kho. Qhov no yog ib qho teeb meem sib npaug: peb tau 0.20.4=0.08.

ntxiv theorem conditional probability multiplication theorem
ntxiv theorem conditional probability multiplication theorem

Qhov tshwm sim yog dab tsi uas koj yuav tau txais tam sim ntawd rau tus neeg raug? Yooj yim dua qhov yooj yim: 0.80.7=0.56. Qhov no, koj pom tias lub xov tooj ua haujlwm thiab ua tiav hu.

Thaum kawg, xav txog qhov xwm txheej no: koj tau txais lub xov tooj tawg, kho nws, tom qab ntawd hu rau tus lej, thiab tus neeg nyob sab nraud teb xov tooj. Ntawm no, qhov sib npaug ntawm peb yam twb xav tau: 0, 20, 40, 7=0, 056.

Thiab ua li cas yog tias koj muaj ob lub xov tooj tsis ua haujlwm ib zaug? Yuav ua li cas koj yuav kho yam tsawg kawg ib ntawm lawv? Qhov no yog ib qho teeb meem ntawm kev sib ntxiv thiab kev sib npaug ntawm qhov tshwm sim, txij li kev sib koom ua ke tau siv. Luas: 0, 4 + 0, 4 - 0, 40, 4=0, 8 - 0, 16=0, 64.

siv ceev faj

Raws li tau hais nyob rau hauv qhov pib ntawm tsab xov xwm, kev siv qhov kev xav ntawm qhov tshwm sim yuav tsum tau txiav txim siab thiab nco qab.

Qhov kev sim loj dua, qhov ze dua qhov kev kwv yees kwv yees tus nqi nce mus txog qhov ua tau zoo. Piv txwv li, peb tab tom pov ib npib. Raws li kev xav, paub txog qhov muaj nyob ntawm cov qauv rau kev sib ntxiv thiab sib npaug ntawm qhov tshwm sim, peb tuaj yeem kwv yees pes tsawg zaus lub taub hau thiab tails yuav poob yog tias peb ua qhov kev sim 10 zaug. Peb tau ua ib qho kev sim thiabCoincidentally, qhov piv ntawm cov poob sab yog 3 mus rau 7. Tab sis yog hais tias koj ua ib tug series ntawm 100, 1000 los yog ntau tshaj sim, nws hloov tawm hais tias lub tis daim duab tau los ze zog mus rau lub theoretical ib: 44 mus rau 56, 482 rau. 518 thiab os.

sib ntxiv thiab sib npaug ntawm qhov tshwm sim ntawm cov xwm txheej ywj pheej
sib ntxiv thiab sib npaug ntawm qhov tshwm sim ntawm cov xwm txheej ywj pheej

Tam sim no xav txog tias qhov kev sim no tau ua tsis yog nrog lub npib, tab sis nrog kev tsim cov tshuaj tshiab tshiab, qhov tshwm sim uas peb tsis paub. Peb yuav khiav 10 qhov kev sim thiab, yog tias peb tsis tau txais txiaj ntsig zoo, peb tuaj yeem hais dav dav: "cov khoom tsis tuaj yeem tau txais." Tab sis leej twg paub, yog peb ua qhov thib kaum ib, peb puas tau mus txog lub hom phiaj los tsis?

Yog li yog tias koj nkag mus rau hauv qhov tsis paub, thaj chaw tsis tau tshawb nrhiav, qhov kev xav ntawm qhov tshwm sim yuav tsis siv. Txhua qhov kev sim tom ntej hauv qhov no tuaj yeem ua tiav thiab kev nthuav dav zoo li "X tsis muaj nyob" lossis "X tsis yooj yim sua" yuav ntxov ntxov.

kaw lo lus

Yog li peb tau saib ob hom kev sib ntxiv, sib npaug thiab qhov yuav tshwm sim. Nrog rau kev kawm ntxiv ntawm thaj chaw no, nws yuav tsum tau kawm paub qhov txawv ntawm qhov xwm txheej thaum txhua tus qauv siv. Tsis tas li ntawd, koj yuav tsum nkag siab seb txoj kev yuav ua li cas feem ntau siv tau los daws koj qhov teeb meem.

sib ntxiv thiab sib npaug ntawm qhov ua piv txwv ntawm cov teeb meem
sib ntxiv thiab sib npaug ntawm qhov ua piv txwv ntawm cov teeb meem

Yog tias koj xyaum, tom qab ib ntus koj yuav pib ua txhua yam haujlwm uas xav tau tshwj xeeb hauv koj lub siab. Rau cov neeg uas nyiam daim npav ua si, qhov kev txawj no tuaj yeem xav txogtsis tshua muaj txiaj ntsig - koj yuav ua rau kom koj txoj hauv kev muaj yeej, tsuas yog los ntawm kev suav qhov tshwm sim ntawm ib daim npav tshwj xeeb lossis nplua poob tawm. Txawm li cas los xij, qhov kev paub uas tau txais tuaj yeem siv tau yooj yim hauv lwm qhov haujlwm.

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