document.write( "Question 1166409: a fire system has seven fail safe components. The probability of each failing is 0.07. Find these probabilities.
\n" ); document.write( "1. exactly 4 will fail
\n" ); document.write( "2.More then four will fail
\n" ); document.write( "

Algebra.Com's Answer #790934 by solver91311(24713)\"\" \"About 
You can put this solution on YOUR website!
\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The probability of successes in trials where the probability of success on any given trial is is given by:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The probability of at most successes in trials where the probability of success on any given trial is is given by:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The probability of at least successes in trials where the probability of success on any given trial is is given by:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The probability of more than successes in trials where the probability of success on any given trial is is given by:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "{k},n,p)\ =\ \sum_{r=k+1}^n\,{{n}\choose{r}},(p)^r(1\,-\,p)^{n-r}\">\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Make adjustments to the summation indices depending on exactly what you are looking for. Also note the following relationship that may save you some arithmetic:\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "{k},n,p)\ =\ 1\ -\ P(\leq{k},n,p)\">\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "John
\n" ); document.write( "
\n" ); document.write( "My calculator said it, I believe it, that settles it
\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I > Ø
\n" ); document.write( "
\n" ); document.write( "
\n" );