document.write( "Question 1198800: Use a normal approximation to find the probability of the indicated number of voters. In this case, assume that 124 eligible voters aged 18-24 are randomly selected. Suppose a previous study showed that among eligible voters aged 18-24, 22% of them voted.
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Algebra.Com's Answer #832451 by ikleyn(52793) $\"\"$ $\"About$

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\n" ); document.write( "Use a normal approximation to find the probability of the indicated number of voters.
\n" ); document.write( "In this case, assume that 124 eligible voters aged 18-24 are randomly selected.
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\n" ); document.write( "Find the probability that exactly 30 voted
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document.write( "This problem is on Binomial distribution\r\n" );
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document.write( "    n = 124 total trials;  p = 0.22 is the probability of an individual success;\r\n" );
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document.write( "    k = 30 is the number of successful trials.\r\n" );
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document.write( "Since the number of trials is great, we use the normal distribution as an approximation.\r\n" );
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document.write( "The mean is  m = n*p = 124*0.22 = 27.28;  the standard deviation is  \r\n" );
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document.write( "    SD =  =  = 4.61285  (rounded).\r\n" );
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document.write( "Now you can use your calculator\r\n" );
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document.write( "    p = normalcfd( 29.5, 30.5, 27.28, 4.61285) = 0.0726  (rounded).    ANSWER\r\n" );
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document.write( "The numbers 29.5 and 30.5 come with the continuity correction.\r\n" );
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