document.write( "Question 1028526: A die is rolled 480 times. Find the mean, variance, and
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Algebra.Com's Answer #643673 by Edwin McCravy(20056) $\"\"$ $\"About$

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document.write( "A die is rolled 480 times.  Find the mean, variance, and standard \r\n" );
document.write( "deviation of the number of 3's that will be rolled.  Is it unusual \r\n" );
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document.write( "This is a binomial probability, with , \r\n" );
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document.write( "An event is unusual if the probability of occurring is less than\r\n" );
document.write( "5% or 0.05, which will be an event whose measure is more than 1.645\r\n" );
document.write( "standard deviations either above or below the mean.\r\n" );
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document.write( "100 is 20 more than the mean. 1.645 times the standard deviation\r\n" );
document.write( "is 13.431.  So indeed '20 more than the mean' is more than '13.431\r\n" );
document.write( "more than the mean', so it is unusual to roll 100 3's out of 480 times.\r\n" );
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document.write( "Edwin

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