document.write( "Question 1205234: In a recent year 8,073,000 male students and 10,980,000 female students were
\n" ); document.write( "enrolled as undergraduates. Receiving aid were 60.6% of the male students and
\n" ); document.write( "65.2% of the female students. Of those receiving aid, 44.8% of the males got
\n" ); document.write( "federal aid and 50.4% of the females got federal aid. Choose 1 student at random.
\n" ); document.write( "(Hint: Make a tree diagram.) Find the probability that the student is
\n" ); document.write( "a. A male student without aid
\n" ); document.write( "b. A male student, given that the student has aid
\n" ); document.write( "c. A female student or a student who receives federal aid
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Algebra.Com's Answer #842319 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "I'll use a two-way table instead of a tree diagram.\r
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\n" ); document.write( "\n" ); document.write( "Here's the starting template
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MaleFemaleTotal
Aid
No Aid
Total

\n" ); document.write( "Place the values 8,073,000 and 10,980,000 at the bottom row of the male and female columns respectively.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "60.6% of 8,073,000 = 0.606*(8,073,000) = 4,892,238 male students got aid.
\n" ); document.write( "65.2% of 10,980,000 = 0.652*(10,980,000) = 7,158,960 female students got aid.\r
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\n" ); document.write( "\n" ); document.write( "Let's place those results into the table.
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "
MaleFemaleTotal
Aid4,892,2387,158,96012,051,198
No Aid
Total8,073,00010,980,00019,053,000
\r
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\n" ); document.write( "\n" ); document.write( "To finish up the table, subtract the count who got aid from the total.
\n" ); document.write( "Eg: 8,073,000 - 4,892,238 = 3,180,762 male students did not get aid.\r
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\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "
MaleFemaleTotal
Aid4,892,2387,158,96012,051,198
No Aid3,180,7623,821,0407,001,802
Total8,073,00010,980,00019,053,000
\r
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\n" ); document.write( "\n" ); document.write( "Of those who got aid, we have this sub-table
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "
MaleFemaleTotal
Federal2,191,7233,608,1165,799,839
Not federal2,700,5153,550,8446,251,359
Total4,892,2387,158,96012,051,198

\n" ); document.write( "Example: 44.8% of 4,892,238 = 0.448*4892238 = 2191722.624 which rounds to 2191723\r
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\n" ); document.write( "\n" ); document.write( "The values in the bottom row match up with the values in row 1 of the previous table. Spreadsheet software is strongly recommended.\r
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\n" ); document.write( "\n" ); document.write( "-------------------------------------------------\r
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\n" ); document.write( "\n" ); document.write( "Part (a)\r
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\n" ); document.write( "\n" ); document.write( "Refer to the first table
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MaleFemaleTotal
Aid4,892,2387,158,96012,051,198
No Aid3,180,7623,821,0407,001,802
Total8,073,00010,980,00019,053,000
\r
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\n" ); document.write( "\n" ); document.write( "There are 3,180,762 men who did not get aid out of 19,053,000 students.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3180762/19053000 = 0.166943 approximately\r
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\n" ); document.write( "\n" ); document.write( "-------------------------------------------------\r
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\n" ); document.write( "\n" ); document.write( "Part (b)\r
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\n" ); document.write( "\n" ); document.write( "Refer to the same table as mentioned in part (a)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The key term \"given\" means we know 100% that whoever is randomly selected, they received aid of some kind (federal or non-federal).
\n" ); document.write( "We focus entirely on the \"aid\" row.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "There are 4,892,238 men who got aid out of 12,051,198 students who got aid.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "4892238/12051198 = 0.405954 approximately\r
\n" ); document.write( "\n" ); document.write( "-------------------------------------------------\r
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\n" ); document.write( "\n" ); document.write( "Part (c)\r
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\n" ); document.write( "\n" ); document.write( "We'll need to use this table
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MaleFemaleTotal
Aid4,892,2387,158,96012,051,198
No Aid3,180,7623,821,0407,001,802
Total8,073,00010,980,00019,053,000

\n" ); document.write( "and this table as well
\n" ); document.write( "\n" ); document.write( "\n" ); document.write( "
MaleFemaleTotal
Federal2,191,7233,608,1165,799,839
Not federal2,700,5153,550,8446,251,359
Total4,892,2387,158,96012,051,198

\n" ); document.write( "There's probably a clever way to combine the two tables, but my mind is drawing a blank right now.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "There are 10,980,000 female students and 5,799,839 students who got federal aid. The overlap is the 3,608,116 female students who got federal aid.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Use the inclusion exclusion principle to say that there are
\n" ); document.write( "10980000+5799839-3608116 = 13171723
\n" ); document.write( "students who are female, got federal aid, or both.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This is out of the 19053000 students total.
\n" ); document.write( "13171723/19053000 = 0.69132 approximately.\r
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\n" ); document.write( "\n" ); document.write( "Summary
\n" ); document.write( "(a) 0.166943
\n" ); document.write( "(b) 0.405954
\n" ); document.write( "(c) 0.69132
\n" ); document.write( "Each value is approximate. Round them however needed.
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