Cov txheej txheem:
Video: Yuav ua li cas koj xam random variation?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
A Random Variable yog ib txheej ntawm qhov ua tau los ntawm a random kev sim.
Txhawm rau xam qhov Variance:
- square txhua tus nqi thiab muab faib los ntawm nws qhov tshwm sim.
- sum lawv thiab peb tau Σx2p.
- tom qab ntawd rho tawm cov square ntawm qhov xav tau tus nqi μ
Nyob rau hauv no, dab tsi yog ib tug random variation?
Cov hloov pauv uas muaj nyob rau hauv tus txheej txheem uas tsis tuaj yeem txiav txim siab. Cov kev hloov pauv no thiab kev hloov pauv yog tshwm sim los ntawm erratic thiab irregular yam uas yog tshwm sim los ntawm random caij nyoog. Cov no random variations tsis tuaj yeem raug tshem tawm lossis txiav txim siab.
Tsis tas li ntawd, koj ua li cas xam cov qauv sib txawv? Txoj Kev 1 xam qhov txawv ntawm ib qho qauv
- Sau koj cov qauv ntaub ntawv teev tseg.
- Sau cov qauv variance qauv.
- Xam qhov nruab nrab ntawm tus qauv.
- Tshem tawm qhov nruab nrab ntawm txhua qhov chaw cov ntaub ntawv.
- Square txhua qhov tshwm sim.
- Nrhiav qhov sum ntawm cov nqi squared.
- Faib los ntawm n - 1, qhov twg n yog tus naj npawb ntawm cov ntsiab lus.
Ib yam li ntawd, koj pom qhov txawv ntawm qhov sib txawv li cas?
Txhawm rau xam qhov sib txawv ua raws cov kauj ruam no:
- Ua Haujlwm Tawm Qhov Ntsuas (qhov nruab nrab yooj yim ntawm cov lej)
- Tom qab ntawd rau txhua tus lej: rho tus Mean thiab square qhov tshwm sim (qhov sib txawv squared).
- Ces ua hauj lwm tawm qhov nruab nrab ntawm cov squared sib txawv. (Vim li cas Square?)
Dab tsi ua rau random variation?
Lub ntsiab lus ntawm Common Ua Variation : Feem ntau ua rau variation yog fluctuation tshwm sim los ntawm tsis paub yam uas ua rau ib tug khov kho tab sis random kev faib tawm ntawm cov zis nyob ib ncig ntawm qhov nruab nrab ntawm cov ntaub ntawv. Nws yog ib qho kev ntsuas ntawm cov txheej txheem muaj peev xwm, lossis cov txheej txheem tuaj yeem ua tau zoo npaum li cas thaum tshwj xeeb ua rau variation tshem tawm.
Pom zoo:
Yuav ua li cas koj xam tus qauv sib txawv ntawm PMP?
Cov mis siv nyob rau hauv PMBOK rau tus qauv sib txawv yog yooj yim. Nws tsuas yog (P-O) / 6. Qhov ntawd yog qhov pessimistic kev ua ub no kwv yees rho tawm qhov kev kwv yees qhov kev xav tau muab faib los ntawm rau. Qhov teeb meem yog qhov no nyob rau hauv tsis muaj txoj kev zoo los yog daim ntawv tsim ib qho kev ntsuas ntawm tus qauv deviation
Yuav ua li cas koj xam qhov ncig ntawm lub ntiaj teb ntawm nws latitude?
Circumference ntawm lub voj voog yog sib npaug rau 2 π r qhov twg r yog nws lub vojvoog. Nyob rau hauv lub ntiaj teb no, lub circumference ntawm tus kheej ntawm ib tug muab latitude yog 2πr(cos θ) qhov twg θ yog lub latitude thiab r yog lub vojvoog ntawm lub ntiaj teb ntawm kab zauv
Yuav ua li cas koj sau ib tug ncaj variation sib npaug?
Txij li thaum k yog qhov tsis tu ncua (zoo ib yam rau txhua lub ntsiab lus), peb tuaj yeem pom k thaum muab ib qho taw tes los ntawm kev faib y-coordinate los ntawm x-coordinate. Piv txwv li, yog tias y sib txawv ncaj qha li x, thiab y = 6 thaum x = 2, qhov kev hloov pauv tsis tu ncua yog k = = 3. Yog li, qhov sib npaug piav qhia qhov kev hloov pauv ncaj qha yog y = 3x
Yuav ua li cas koj xam lub sij hawm nws yuav siv sij hawm mus ncig teb chaws?
Kwv yees seb koj yuav mus sai npaum li cas ntawm koj qhov kev mus ncig. Tom qab ntawd, faib koj qhov kev ncua deb ntawm koj qhov nrawm. Qhov no yuav muab rau koj anestimation ntawm koj lub sijhawm mus ncig. Piv txwv li, yog tias koj mus ncig yog 240 mais thiab koj yuav tsav 40 mais ib teev, koj lub sijhawm yuav yog 240/40 = 6hours
Yuav ua li cas koj xam lub sij hawm nws yuav siv ib yam khoom los poob?
Ntsuas qhov deb ntawm qhov khoom yuav poob hauv ko taw nrog tus pas ntsuas lossis ntsuas daim kab xev. Faib qhov kev ncua deb los ntawm 16. Piv txwv li, yog tias cov khoom yuav poob 128 ko taw, faib 128 los ntawm 16 kom tau 8. Xam cov square root ntawm cov kauj ruam 2 los nrhiav lub sij hawm nws yuav siv cov khoom poob hauv vib nas this