[sadie]

حل سؤال 23 ص 222
An insurance company classifies drivers as low risk, medium risk, and high risk of those insured, 60% are low risk, 30% are medium risk, and 10% are high risk. After a study, the company finds that during a one year period, 1% of the low risk drivers had an accident, 5% of the medium risk drivers had an accident, and 9% of the high risk drivers had an accident. If a driver is selected at random, find the probability that the driver will have had an accident during the year

الحل :
low = 0.60
medium= 0.30
high =0.10

هذه اعتبريها زي كأنه كور في صندوق و هنا بس اعطاك النسب حقتهم

وبعدين اعطاكي احتمالات انهم have an accident

low = 0.01
medium =0.05
high = 0.09

وبعدين قالك If a driver is selected at random, find the probability that the driver will have had an accident during the year

هو ما اعطاكي من فئة معينة ولا شي هو قالك بس ماهو احتمال انه يصير له حادث وسكت

في هذه الحاله كأنك قاعدة تقولي
احتمال انه يصير له حادث يا اما يكون من فئة low و احتمال انه يصير له حادث 0.01 او انه يكون من فئة medium واحتمال انه يصير له حادث 0.05 او انه يكون من فئة high واحتمال انه يصير له حادث 0.09

او تتحول لجمع
و تتحول لضرب


وبالانجليزي

from low risk 0.60 and the probability that driver will have had an accident is 0.01 or from medium risk 0.30 and the probability that driver will have had an accident is 0.05 or from high risk 0.10 and the probability that driver will have had an accident is 0.09

or تتحول جمع
and تتحول ضرب


وتضربي الاحتمال بنسبة الفئة

فالحل يكون كدا

(0.60 * 0.01) + (0.30 * 0.05) + (0.10 * 0.09) = 0.03



وبس ^^