SOLUTION: in a school,45% of the students are boys and 55% are girls. in this school, 12% of the boys are left handed and 9% of the girls are left handed. a student is to be chosen at random

Algebra ->  Probability-and-statistics -> SOLUTION: in a school,45% of the students are boys and 55% are girls. in this school, 12% of the boys are left handed and 9% of the girls are left handed. a student is to be chosen at random      Log On


   

Question 375910: in a school,45% of the students are boys and 55% are girls. in this school, 12% of the boys are left handed and 9% of the girls are left handed. a student is to be chosen at random using a tree diagram
a) calculate the probability that the student is not left handed
Given that the student chosen is left handed,
b)calculate, to 3 significant figures,the probabillity that the student is a girl
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
We can't do tree diagrams on this site.
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a) (.45*.88)+(.55*.91)=.8965
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b)
.45*.12=.0540 LHB
.55*.09=.0495 LHG
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=======>.1035 Total LH
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.0495/.1035 = .478 Given that the student chosen is left handed, the probabillity that the student is a girl.
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Ed