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Classical Probability

Roba Al-Khereiji

Leen Basoman

Maryam BarifahRaghda Elzahrana

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We se !robability almoste"ery single day of orli"es #ithot e"en$no#ing% &rom the #eatherforecast to #hich lane yota$e #hile dri"ing and e"en#hat yo chose to #ear all

se !robability%

'o #hat is !robability(

)t*s a mathematical termsed to describe theli$elihood of somethingha!!eningAlthogh #e can*t actally

!redict the ftre #ith

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Classical Probability

Classical !robability is based on the follo#ingassm!tions,

% Randomness: ALL otcomes are equally likely.they ha"e the same !robability of occrring/%

0% Defniteness: ALL !ossible otcomes areidenti1ed and can be conted%

Classical !robability is the nmerical li$elihoodthat a s!eci1c e"ent #ill occr2 and it is fondthrogh the se of the sam!le s!ace% Classical

!robability can be determined by eithere3!erimental methods or calclation%

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CLA'')CAL PR4BAB)L)56 &4RM7LA

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Probabilities can be e3!ressed as fractions2decimals2 or !ercentages%

5here are s!eci1c rles for ronding !robabilities% )nthe case of fractions2 they shold be e3!ressed intheir redced form% )n the case of decimals2 theyshold be ronded to the third decimal !lace% )f thedecimal #as e3tremely small .e3, 8%888888889:/2 it

is acce!table to rond to the 1rst non-zero digit .e3,8%88888888;/%

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? "s%

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E3am!les

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E3am!les

0:

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E3am!les

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Probability Rles

% 5he !robability of any e"entE is nmber .either

fraction or decimal/ bet#een and inclding 8 and %0% 5he sm of the !robabilities of all the otcomes in a

sam!le s!ace is %% )f an e"ent E cannot occr2 its !robability is 8%% )f an e"ent E is certain2 then the !robability of E is

one%

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Com!lementary E"ents

5he sam!le s!ace consists of the otcomes

2 02 2 2 D2 and :%5he e"ent .A/ of nmbers is D and :%5he e"en of not getting D or : is called thecom!lement of e"ent .A/%

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Marbles Acti"ity

%5he !robability of retrie"ing a light blemarble from the bo3 is%%%

0%5he !robability of retrie"ing a blac$ ororange marble is%%%

%)f both gro!s #ere to retrie"e amarble from their bo3es at the sametime2 the !robabilty that they #oldretrie"e a dar$ ble marble and agreen marble is%%%