document.write( "Question 1176603: Suppose a football player has a 65% chance of making a goal that he can keep each time he tries to make a goal. What is the probability that he makes a goal for the first three times he tries to but not on the fourth try? \n" ); document.write( "

Algebra.Com's Answer #803813 by ikleyn(52809) $\"\"$ $\"About$

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\n" ); document.write( "Suppose a football player has a 65% chance of making a goal that he can keep each time he tries to make a goal.
\n" ); document.write( "What is the probability that he makes a goal for the first three times he tries to but not on the fourth try?
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\n" ); document.write( "\n" ); document.write( " The solution by @ewatrrr is incorrect.\r
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\n" ); document.write( "\n" ); document.write( " I came to bring the correct solution.\r
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document.write( "This problem asks about the probability to make one goal in first three trials AND do not make it in the fourth trial.\r\n" );
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document.write( "So, it is the probability of intersection of two independent events:\r\n" );
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document.write( "    - first event is to make one goal in first three attepts,\r\n" );
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document.write( "and\r\n" );
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document.write( "    - the second event is do not make a goal in the fourth attempt.\r\n" );
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document.write( "For the first event we have a Binomial distribution problem\r\n" );
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document.write( "     =  =  = 0.2389   (rounded).\r\n" );
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document.write( "For the second event we have the probability\r\n" );
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document.write( "     = 1 - 0.65 = 0.35.\r\n" );
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document.write( "Thus the final formula and the answer to the problem's question are\r\n" );
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document.write( "    P =  = 0.2389*0.35 = 0.0836.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "After seeing my post, @ewatrrr made some corrections, but they are partly incomplete and parly incorrect,\r
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\n" ); document.write( "\n" ); document.write( "so her final answer and the formulas are and remain INCORRECT.\r
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\n" ); document.write( "\n" ); document.write( "When she comments about different approaches, she makes it WRONG, too.\r
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\n" ); document.write( "\n" ); document.write( "The right comment is THIS:\r
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document.write( "    - her approach was INCORRECT,\r\n" );
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document.write( "    - while my approach is a UNIQUALLY RIGHT.\r\n" );
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