document.write( "Question 664071: I am a salesperson & I close on 70% of all my sales. If I call on 4 sales, what is the probability that I will close on 3 of the 4 sales? \n" ); document.write( "
Algebra.Com's Answer #852492 by ikleyn(52957)\"\" \"About 
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\n" ); document.write( "I am a salesperson & I close on 70% of all my sales. If I call on 4 sales, what is the probability
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\n" ); document.write( "\n" ); document.write( "        In the post by @Theo, there are too many words and too many excessive calculations.\r
\n" ); document.write( "\n" ); document.write( "        It is not a mathematical style solving and not a good style teaching.\r
\n" ); document.write( "\n" ); document.write( "        I came to provide a solution in the form as it should be done and presented.\r
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document.write( "This problem is on Binomial distribution.\r\n" );
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document.write( "The number of trials is 4.  The probability of a success at each individual trial is p = 0.7.\r\n" );
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document.write( "They want you find the probability of having 3 success in 4 trials.\r\n" );
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document.write( "Use the formula for binomial distribution\r\n" );
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document.write( "    P(n=4; k=3; p=0.7) = \"C%284%2C3%29%2Ap%5E3%2A%281-p%29%5E1\",\r\n" );
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document.write( "where  C(4.3) = \"4%21%2F3%21\" = \"%281%2A2%2A3%2A4%29%2F%281%2A2%2A3%29\" = 4 is the binomial coefficient.\r\n" );
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document.write( "The formula gives\r\n" );
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document.write( "    P = \"4%2A0.7%5E3%2A0.3\" = 0.4116.\r\n" );
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document.write( "ANSWER.  The probability to close 3 sales of 4 sales in this problem is 0.4116.\r\n" );
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\n" ); document.write( "\n" ); document.write( "As you solve your problems on Binomial distribution, when you treat this given problem
\n" ); document.write( "among many others problems of this topic, two moments are important: \r
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\n" ); document.write( "\n" ); document.write( "        (a)  to recognize from the text that this given problem is on Binomial distribution, \r
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\n" ); document.write( "\n" ); document.write( "        (b)  to apply an appropriate formula of the binomial distribution.\r
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\n" ); document.write( "\n" ); document.write( "These are the key.   The rest is pure mechanical job for a calculator.\r
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