document.write( "Question 450068: At Med U. the failure rate is 20%. Of 15 students registered in the freshman class;
\n" ); document.write( "What is the probability that they all pass?
\n" ); document.write( "What is the probability that a least 1 fails?
\n" ); document.write( "How many freshman are likely to pass?\r
\n" ); document.write( "\n" ); document.write( "An algebra class has 18 girls and 14 boys. Five tickets to a concert have just been made available to the class. The students to get the tickets will be chosen at random. What is the probability that:
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\n" ); document.write( "b) five boys are chosen?
\n" ); document.write( "c) at least 1 girl is chosen?
\n" ); document.write( "d) How many girls are likely to be chosen?\r
\n" ); document.write( "\n" ); document.write( "Thanks so much for your help!
\n" ); document.write( "Shauna \n" ); document.write( "

Algebra.Com's Answer #309639 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!

 
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document.write( "Hi,
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document.write( "Note: The probability of x successes in n trials is: 
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document.write( "P = nCx*  where p and q are the probabilities of success and failure respectively. 
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document.write( "In this case p(failing) = .20 and q(passing) = .80   |the failure rate is 20%.
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document.write( "nCx = 
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document.write( "Of 15 students registered in the freshman class;
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document.write( " P(all pass) = (.80)^15 = .0352
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document.write( "P(at least 1 fails) = 1 - P(none failing) = 1 - .0352 = .9648
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document.write( "How many freshman are likely to pass? .80*15 = 12\r
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document.write( "\n" );
document.write( "An algebra class has 18 girls and 14 boys. 
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document.write( "Five tickets to a concert have just been made available to the class. 
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document.write( "The students to get the tickets will be chosen at random.
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document.write( "What is the probability that:
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document.write( "a) five girls are chosen = 18C5/32C5 = 8568/201,376 = .0425
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document.write( "  nCx =   18C5 =  18!/(5!13!) and 32C5 = 32!/5!27!
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document.write( "These can be found with a calculator that has a factorial function.\r
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document.write( "b) five boys are chosen = 14C5/32C5 = 2002/201,376 = .0099
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document.write( "c) at least 1 girl is chosen? 1 - P(all boys) = 1 - .0099 = .9901
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document.write( "d) How many girls are likely to be chosen? (18/32)*5 = 2.8  
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