document.write( "Question 129435: Suppose that it is known that 5% of the items produced by a particular machine are defective in some way, and that we will choose a random sample of exactly 20 parts made by this machine.
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document.write( "a.What is the expected number of defective items, out of the 20 we select?\r
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document.write( "b.What is the probability that exactly 1 of the 20 items is defective?\r
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document.write( "c. what is the probability that no more than 2 out of the 20 items selected are defective. \r
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Algebra.Com's Answer #94548 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! Suppose that it is known that 5% of the items produced by a particular machine are defective in some way, and that we will choose a random sample of exactly 20 parts made by this machine. \n" ); document.write( "a.What is the expected number of defective items, out of the 20 we select? \n" ); document.write( "0.05*20 = 1 \n" ); document.write( "--------------------------- \n" ); document.write( "b.What is the probability that exactly 1 of the 20 items is defective? \n" ); document.write( "P(x=1) = 20C1(0.05)(0.95)^19 = 0.377... \n" ); document.write( "----------------------------- \n" ); document.write( "c. what is the probability that no more than 2 out of the 20 items selected are defective. \n" ); document.write( "P(0<=x<=2) = binomcdf(20,0.05,2)= 0.9245... \n" ); document.write( "---------- \n" ); document.write( "Comment: The binomcdf is a function on a TI calculator. \n" ); document.write( "For example binomcdf(20,0,05,2) = 20C0(0.05)^0+0.95^20 + 20C1(0.05)(0.95)^19 \n" ); document.write( "+ 20C2(0.05)^2(0.95)^18 = 0.9245... \n" ); document.write( "=========================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |