document.write( "Question 1197515: An electronic system has four components labeled as 1, 2, 3, and 4. The system has to
\n" ); document.write( "be used during a given time period. The probability that component 𝑖 will fail during
\n" ); document.write( "that time period is Fi
\n" ); document.write( "for 𝑖 = 1, …, 4. Failures of the components are physically
\n" ); document.write( "independent of each other. A system failure occurs if component 1 fails or if at least
\n" ); document.write( "two of the other components fail. Specify an appropriate sample space and determine
\n" ); document.write( "the probability of a system failure.
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Algebra.Com's Answer #830814 by ikleyn(52781)\"\" \"About 
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\n" ); document.write( "An electronic system has four components labeled as 1, 2, 3, and 4. The system has to
\n" ); document.write( "be used during a given time period. The probability that component 𝑖 will fail during
\n" ); document.write( "that time period is Fi
\n" ); document.write( "for 𝑖 = 1, …, 4. Failures of the components are physically
\n" ); document.write( "independent of each other. A system failure occurs if component 1 fails or if at least
\n" ); document.write( "two of the other components fail. Specify an appropriate sample space and determine
\n" ); document.write( "the probability of a system failure.
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\n" ); document.write( "\n" ); document.write( "        If the final goal is to determine the probability for the whole system to fail, then
\n" ); document.write( "        it is much simpler to solve the problem without considering the appropriate sample space.\r
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\n" ); document.write( "\n" ); document.write( "        Formula  (1)  below replaces considering sample space.\r
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document.write( "If  \"F%5Bi%5D\"  is the probability to fail for i-th component,\r\n" );
document.write( "then the probability not to fail for this component is \"G%5Bi%5D\" = 1 - \"F%5Bi%5D\".\r\n" );
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document.write( "Now the probability for the whole system to fail is\r\n" );
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document.write( "    P = P(1st component failed) + P(1st is good, 2nd failed,  3rd failed,  4th is good)   + \r\n" );
document.write( "                                + P(1st is good, 2nd failed,  3rd is good, 4th failed)    + \r\n" );
document.write( "                                + P(1st is good, 2nd is good, 3rd failed,  4th failed)    + \r\n" );
document.write( "                                + P(1st is good, 2nd failed,  3rd failed,  4th failed).      (1)\r\n" );
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document.write( "It is the same as\r\n" );
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document.write( "    P = \"F%5B1%5D\" +  + \"%281-F%5B1%5D%29%2AF%5B2%5D%2AF%5B3%5D%2AF%5B4%5D\" = \r\n" );
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document.write( "      = \"F%5B1%5D\" +  + \"%281-F%5B1%5D%29%2AF%5B2%5D%2AF%5B3%5D%2AF%5B4%5D\".    ANSWER\r\n" );
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