document.write( "Question 1143213: The dress code at a North High School allows students to wear blue or white
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\n" ); document.write( "A group of students was observed and their shirt color was recorded.\r
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\n" ); document.write( " males females
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\n" ); document.write( "What is the probably that a student chosen is wearing a blue shirt if you
\n" ); document.write( "already know the student is a female P(B|F)?
\n" ); document.write( "Round answers to hundredths as needed.
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Algebra.Com's Answer #764008 by Edwin McCravy(20064)\"\" \"About 
You can put this solution on YOUR website!
The dress code at a North High School allows students to wear blue or white
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document.write( "         males    females\r\n" );
document.write( "--------------------------\r\n" );
document.write( "blue |     26   |    73\r\n" );
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document.write( "white|     62   |    41\r\n" );
document.write( "--------------------------  \r\n" );
document.write( "  \r\n" );
document.write( "When you have a chart like this, you should always add on \r\n" );
document.write( "a third column and a third row to the table for the totals,\r\n" );
document.write( "like below.  Then you can answer any question they give you.\r\n" );
document.write( "  \r\n" );
document.write( "           males   females  totals\r\n" );
document.write( "-----------------------------------\r\n" );
document.write( "blue  |     26   |    73   |  99  |\r\n" );
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document.write( "white |     62   |    41   | 103  | \r\n" );
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document.write( "totals|    88    |   114   | 202  |\r\n" );
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document.write( "Notice that we get the same grand total 202 whether we add the\r\n" );
document.write( "totals of the males and females 99+103 or whether we add the\r\n" );
document.write( "totals of blue shirted people and white shirted people 88+114.\r\n" );
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\n" ); document.write( "What is the probably that a student chosen is wearing a blue shirt if you
\n" ); document.write( "already know the student is a female P(B|F)?
\n" ); document.write( "Round answers to hundredths as needed.
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\r\n" );
document.write( "Since we already know that the student chosen is a female, we\r\n" );
document.write( "can reduce the sample space by eliminating all the males and\r\n" );
document.write( "totals on the right column, since they are not involved:\r\n" );
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document.write( "                   females  \r\n" );
document.write( "-----------------------------------\r\n" );
document.write( "blue  |          |    73   |      |\r\n" );
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document.write( "white |          |    41   |      | \r\n" );
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document.write( "totals|          |   114   |      |\r\n" );
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document.write( "So the probability is 73 out of 114 or 73/114 which equals\r\n" );
document.write( "0.6403508772 which rounds to 0.64\r\n" );
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document.write( "If you had been asked instead:\r\n" );
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\n" ); document.write( "What is the probably that a student chosen is male if you already
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document.write( "Since we already know that the student chosen is wearing a white\r\n" );
document.write( "shirt, we can reduce the sample space by eliminating all the \r\n" );
document.write( "people wearing blue shirts and totals on the bottom, since they are \r\n" );
document.write( "not involved:\r\n" );
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document.write( "           males   females  totals\r\n" );
document.write( "-----------------------------------\r\n" );
document.write( "blue  |          |         |      |\r\n" );
document.write( "-----------------------------------\r\n" );
document.write( "white |     62   |    41   | 103  | \r\n" );
document.write( "-----------------------------------\r\n" );
document.write( "totals|          |         |      |\r\n" );
document.write( "-----------------------------------\r\n" );
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document.write( "So the probability is 62 out of 103 or 62/103 which equals\r\n" );
document.write( "0.6019417476 which rounds to 0.60\r\n" );
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document.write( "Yes I know you weren't asked that but you might be sometime.\r\n" );
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document.write( "Edwin
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