document.write( "Question 1098972: A multiple-choice test consists of 7 questions. Each question has answer choices of a ,b ,c , and d , and only one of the choices is correct. If a student randomly guesses on each question, what is the probability that she gets at most 1 of them correct? \n" ); document.write( "
Algebra.Com's Answer #713382 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "That's a binomial probability problem with n=7 trials, p = 1/4,\r\n" );
document.write( "and x=0 OR x=1\r\n" );
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document.write( "There are two ways, by formula or by graphing calculator.\r\n" );
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document.write( "By formula first (the long way):\r\n" );
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document.write( "\"expr%28n%21%2F%28x%21%28n-x%29%21%29%29p%5Ex%2A%281-p%29%5E%28n-x%29\"\r\n" );
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document.write( "Using x=0\r\n" );
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document.write( "\"expr%287%21%2F%280%21%287-0%29%21%29%29%281%2F4%29%5E0%2A%281-1%2F4%29%5E%287-0%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"expr%287%21%2F%281%287%29%21%29%29%281%29%2A%283%2F4%29%5E7\"\r\n" );
document.write( "\r\n" );
document.write( "\"expr%287%21%2F%287%21%29%29%281%29%2A%283%5E7%2F4%5E7%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"%281%29%281%29%282187%2F16384%29\"\r\n" );
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document.write( "\"2187%2F16384\"\r\n" );
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document.write( "Using x=1\r\n" );
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document.write( "\"expr%287%21%2F%281%21%287-1%29%21%29%29%281%2F4%29%5E1%2A%281-1%2F4%29%5E%287-1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"expr%287%21%2F%281%286%29%21%29%29%281%2F4%29%2A%283%2F4%29%5E6\"\r\n" );
document.write( "\r\n" );
document.write( "\"expr%287%21%2F%286%21%29%29%281%2F4%29%2A%283%5E6%2F4%5E6%29\"\r\n" );
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document.write( "\"7%2A%28729%2F16384%29\"\r\n" );
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document.write( "\"5103%2F16384\"\r\n" );
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document.write( "Use the fact that OR means to ADD\r\n" );
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document.write( "\"2187%2F16384\"\"%22%22%2B%22%22\"\"5103%2F16384\"\r\n" );
document.write( "\r\n" );
document.write( "\"7290%2F16384\"\r\n" );
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document.write( "\"0.4449462891\"\r\n" );
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document.write( "By graphing calculator, if you have a TI-83 or TI-84,\r\n" );
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document.write( "Press 2ND VARS\r\n" );
document.write( "Scroll to binomcdf(\r\n" );
document.write( "Press ENTER\r\n" );
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document.write( "You may or may not see the next screen, depending of\r\n" );
document.write( "the age of your calculator or the settings in MODE\r\n" );
document.write( "If you see this screen, make it read this way:\r\n" );
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document.write( "                binomcdf\r\n" );
document.write( "         trials:7\r\n" );
document.write( "         p:1/4\r\n" );
document.write( "         x value:1\r\n" );
document.write( "         Paste\r\n" );
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document.write( "If you have that screen, scroll to 'Paste' and press ENTER\r\n" );
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document.write( "Whether you have that screen or not you should have this on\r\n" );
document.write( "your main screen, whether you have to type it in or it's\r\n" );
document.write( "already there:\r\n" );
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document.write( "binomcdf(7,1/4,1)\r\n" );
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document.write( "Press ENTER\r\n" );
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document.write( "Read    .4449462884\r\n" );
document.write( "\r\n" );
document.write( "Edwin
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