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Hodisalarning juft-jufti bilan bog„liqmasligidan ularning birgalikda
bog„liqmasligi kelib chiqmaydi.
1-misol. Ikkita mergan
bir-biriga bog„liqmas ravishda bitta nishon-
ga o„q uzmoqda. Birinchi merganning nishonga tekkizish ehtimolligi 0,8
ga, ikkinchi mergan uchun 0,4 ga teng. Agar nishonni yakson qilish
uchun bitta o„q tegishi kifoya bo„lsa, nishonni yakson bo„lish
ehtimolligini toping.
Yechish:
‒ birinchi merganning nishonga tekkizish hodisasi, ‒
ikkinchi merganning nishonga tekkizish hodisasi bog„liqmas hodisalar
bo„ladi. Bu hodisalarning hech bo„lmasa bittasini ro„y berish ehtimolligi
bu hodisalar yig„indisiga teng:
2.2. Hech bo‘lmasa bitta hodisaning ro‘y berish ehtimolligi.
Birgalikda bog„liqmas bir necha hodisalarning yig„indisi ehtimolligini
quyidagi formuladan foydalanib hisoblaymiz:
(⋃
) ∑
∑ (
)
∑ (
)
Biroq hodisalar soni ko„p bo„lganda, bu formuladan foydalanish
katta hisoblashlarga olib kelgani uchun, bunday hollarda boshqa
formuladan foydalanamiz.
hodisa birgalikda bog„liqmas
hodisalarning kamida
biri ro„y berganda ro„y bersin.
Teorema. Birgalikda bog„liqmas
hodisalarning hech
bo„lmaganda birining ro„y berganida ro„y beradigan
hodisaning
ehtimolligi
