Amincewar tazara. Mẽne ne da kuma yadda za a iya amfani?

Amincewar tazara, zo mana daga filin daga statistics. Wannan wani fanni, abin da hidima ga kimanta da ba a sani ba siga da wani babban mataki na aminci. A mafi sauki hanyar bayyana wannan shi ne tare da wani misali.

Misali kana so ka bincika kowane bazuwar darajar, msl, a uwar garke martani lokaci zuwa abokin ciniki request. Duk lokacin da mai amfani iri daban-daban a takamaiman adireshin, da uwar garke amsa ga shi a daban-daban gudu. Saboda haka, gwajin martani lokaci ne bazuwar. Saboda haka, da amincewa tazara domin sanin da iyakoki da wannan siga, sa'an nan kuma zai yiwu a yi jayayya cewa da yiwuwar 95% na dauki kudi na cikin uwar garke zai kasance a cikin zangon lasafta ta mu.

Ko kana so ka san yadda mutane da yawa suna sane da cinikayya alamar da kamfanin. Lokacin da amincewa tazara da aka lasafta, to, zai yiwu, misali, a ce wani 95% yiwuwa rabo daga masu amfani da suke sane da wannan alama, shi ne a cikin kewayon daga 27% zuwa 34%.

Tun da yake wannan lokaci ne a hankali related to irin wannan darajar a matsayin amincewa da matakin. Yana da wani yiwuwar cewa so wani zaɓi ne kunshe a cikin amincewa tazara. Daga wannan darajar ya dogara kan yadda babban za mu so kewayo. A mafi girma da daraja yana karɓa, da narrower amincewa tazara, da kuma mataimakin versa. Yawanci shi an saita zuwa 90%, 95% ko 99%. The darajar 95% ne mafi m.

Active bangaren kuma rinjayar da watsawa na lura da samfurin size. Its definition dogara ne a kan zato cewa sifa a tambaya shi ne batun da al'ada rarrabuwa dokar. Wannan sanarwa da aka sanshi a matsayin Gauss ta Law. A cewar shi, wannan ne ake kira da al'ada rarraba a ci gaba da bazuwar m cewa za a iya bayyana ta yiwuwa yawa. Idan zato na al'ada rarrabuwa tabbata ba daidai ba, to, da kimanta iya zama daidai ba.

Da farko, bari mu magance yadda za a lissafta da amincewa tazara da fata. Akwai biyu yiwu lokuta. Watsawa (digiri na watsa daga bazuwar m) iya sani ko ba. Idan aka sani, mu amincewa tazara da aka lasafta ta yin amfani da wadannan dabara:

HSR - t * σ / (sqrt (n)) <= α <= HSR + t * σ / (sqrt (n)), a cikinsa

α - ãyã,

t - siga na Laplace rarraba tebur,

sqrt (n) - cikin square tushen daga cikin jimlar samfurin girma ,

σ - square tushen na sãɓã wa jũna.

Idan sãɓã wa jũna ne ba a sani ba, shi za a iya lasafta, idan muka san duk dabi'u na so hali. Don yin wannan, yi amfani da wadannan dabara:

σ2 = h2sr - (HSR) 2, a cikinsa

h2sr - da talakawan tamanin da murabba'ai na karatu hali,

(HSR) 2 - square nufin darajar da halayyar.

Da dabara da wanda a cikin wannan yanayin da aka lasafta amincewa tazara ne dan kadan daban-daban:

HSR - t * s / (sqrt (n)) <= α <= HSR + t * s / (sqrt (n)), a cikinsa

XCP - da samfurin nufi,

α - ãyã,

t - siga da aka samu ta Student rarraba tebur t = t (ɣ; n-1),

sqrt (n) - cikin square tushen da samfurin size,

s - square tushen na sãɓã wa jũna.

Ka yi la'akari da wannan misali. Zaton cewa sakamakon 7 ma'aunai da aka ƙaddara da talakawan darajar da gwajin alama, wanda yake shi ne daidai 30 da samfurin sãɓã wa jũna, sunã daidaita da 36. Ya kamata a samu tare da wani yiwuwar 99% amincewa tazara wanda yana dauke da gaskiya tamanin da auna siga.

Da farko mun ayyana abin ne t: t = t (0,99; 7-1) = 3.71. Amfani da sama dabara, muna samun:

HSR - t * s / (sqrt (n)) <= α <= HSR + t * s / (sqrt (n))

30 - 3.71 * 36 / (sqrt (7)) <= α <= 30 + 3,71 * 36 / (sqrt (7))

21,587 <= α <= 38,413

The amincewa tazara ga bamban da aka lasafta a matsayin shi ne yanayin da a san rõwa, kuma idan akwai wani data a kan ilmin lissafi fata, da kuma kawai a san da darajar unbiased sãɓã wa jũna hakkin batu. Ba za mu ba a nan cikin dabara domin ta lissafi, tun da sun kasance quite hadaddun kuma, idan so, za su iya ko da yaushe a iya samu a kan hanyar sadarwa.

Mun lura kawai cewa amincewa tazara aka dace m amfani da na'urar mai kwakwalwa shirin ko sabis na cibiyar sadarwa, wanda aka kira.