Video: Qhov piv txwv ntawm pejxeem yog dab tsi?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Dab tsi yog qhov Peev pejxeem ? A pejxeem proportions yog ib feem ntawm cov pej xeem uas muaj ib tug yam ntxwv. Rau piv txwv , hais tias koj muaj 1,000 tus neeg nyob hauv pej xeem thiab 237 ntawm cov neeg ntawd muaj qhov muag xiav. Ib feem ntawm cov neeg uas muaj qhov muag xiav yog 237 tawm ntawm 1,000, lossis 237/1000.
Ib yam li ntawd, nws yog nug, koj yuav nrhiav tau cov pejxeem li cas?
Formula Tshuaj xyuas p' = x / n qhov twg x sawv cev rau tus naj npawb ntawm kev ua tiav thiab n sawv cev rau tus qauv loj. Qhov sib txawv p' yog tus qauv kev faib ua feem thiab ua tus taw tes kwv yees rau qhov tseeb pejxeem proportions.
Tsis tas li ntawd, tus qauv piv txwv yog dab tsi? Cov piv txwv yog feem ntawm cov qauv uas yog kev vam meej, yog li ntawd. (1) Rau loj, muaj kwv yees li ib txwm faib.
Ib sab saum toj no, qhov sib txawv ntawm qhov piv txwv piv txwv thiab pes tsawg tus pej xeem yog dab tsi?
Yog li ntawd, nws muaj cov txheej txheem ntawm qhov ua tau, qhov kev faib tawm qhov tshwm sim, tus nqi xav tau lossis txhais tau tias, qhov sib txawv, thiab tus qauv sib txawv. Ntawd yog, qhov nruab nrab lossis qhov xav tau ntawm tus nqi piv txwv yog tib yam li cov pejxeem proportions . Nco ntsoov tias qhov no tsis yog nyob ntawm qhov qauv qhov loj los yog qhov pej xeem qhov loj.
Cochran formula yog dab tsi?
Cov Cochran formula tso cai rau koj los laij ib qho piv txwv zoo tshaj plaws uas muab qhov xav tau qib ntawm qhov tseeb, qhov xav tau qib kev ntseeg siab, thiab kwv yees qhov feem ntawm tus cwj pwm tam sim no hauv cov pej xeem. p yog qhov (kwv yees) feem ntawm cov pejxeem uas muaj tus cwj pwm hauv nqe lus nug, · q yog 1 – p.
Pom zoo:
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