Could anyone tell me if I did these correctly!?
- Thread starter Sharnice
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Harry_the_cat
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Looks good to me. I'd just state the odds as "3 to 1".
Dr.Peterson
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I get a different result for 16, using the facts about A and C and A or C.
I agree that 3:1 is better than 3/1, but that depends on how you are taught to write odds.
I agree that 3:1 is better than 3/1, but that depends on how you are taught to write odds.
Harry_the_cat
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Yes Dr P is correct.
I made the same mistake that I think you (Sharnice) did, ie assumed that A, Band C were the only options and so P(A)+P(B)+P(C)=1.
But that is not consistent with the values given for P(A and C) and P(A or C).
Use the fact that P(A or C) = P(A) +P(C) - P(A and C) to calculate the correct value of P(C).
I made the same mistake that I think you (Sharnice) did, ie assumed that A, Band C were the only options and so P(A)+P(B)+P(C)=1.
But that is not consistent with the values given for P(A and C) and P(A or C).
Use the fact that P(A or C) = P(A) +P(C) - P(A and C) to calculate the correct value of P(C).
Dr.Peterson
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Correct. You could also do it using a Venn diagram.
thank you!
I have a question. I didn't notice it last night. for number 16, why isn't the value for P(B and C) =.14 used in the equation to find what P(C) is?
I have a question. I didn't notice it last night. for number 16, why isn't the value for P(B and C) =.14 used in the equation to find what P(C) is?
Dr.Peterson
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Because we don't also know P(B or C), or anything else that could combine with this fact to help us toward that goal.
There are 8 regions in a Venn diagram, so in general you need 8 equations (or given facts) to fully determine the diagram. This problem doesn't allow us to find everything that could be asked, including for example P(B only).
okay got it!