document.write( "Question 40008: Given P(A)=.45, P(B)=.31 calculate:
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Algebra.Com's Answer #25416 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
Given P(A)=.45, P(B)=.31 calculate:\r\n" );
document.write( "P(A|B)\r\n" );
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document.write( "P(B|A)\r\n" );
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document.write( "I do not know the source of this problem.  I'm simply trying \r\n" );
document.write( "to find help for a friend.  She was having trouble with 4 \r\n" );
document.write( "problems that she was trying to understand.  I told her about \r\n" );
document.write( "the wonderful online math resources that are available.  Thank\r\n" );
document.write( " you for any help in helping her understand these types of \r\n" );
document.write( "problems.\r\n" );
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document.write( "P(A|B) means \"the probability that A is true if you \r\n" );
document.write( "are GIVEN that B is true\".\r\n" );
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document.write( "You must be given P(A&B), the probability that both A and B\r\n" );
document.write( "are true at the same time in order to calculate P(A|B) or \r\n" );
document.write( "P(B|A)\r\n" );
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document.write( "The formulas are\r\n" );
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document.write( "          P(A&B)                   P(A&B)\r\n" );
document.write( "P(A|B) = 覧覧覧覧    and P(B|A) = 覧覧覧覧\r\n" );
document.write( "           P(B)                     P(A)\r\n" );
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document.write( "If you had, say P(A)=.45, P(B)=.31 and P(A&B) were, say, .2, \r\n" );
document.write( "then you could calculate\r\n" );
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document.write( "P(A|B) = .2/.31 = .6451612903\r\n" );
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document.write( "P(B|A) = .2/.45 = .4444444444  \r\n" );
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document.write( "But without P(A&B) you cannot calculate these.\r\n" );
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document.write( "Edwin\r\n" );
document.write( "AnlytcPhil@aol.com
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