document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230971>Question 230971</A>: <I><SPAN STYLE=\"word-break: break-all;\"> statistics show that 80% of crimes are never solved.suppose a neighborhood district in a large city suffers repeated crimes the police are investigating 6 property crime cases in this district.\r<BR>\n" );
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document.write( "a) what is the probability that none will ever be solved<BR>\n" );
document.write( "b0probability at least one will be solved<BR>\n" );
document.write( "c0expected # of crimes that will be solved and what is the standard deviation </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #171040 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=171040\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> statistics show that 80% of crimes are never solved.suppose a neighborhood district in a large city suffers repeated crimes the police are investigating 6 property crime cases in this district. <BR>\n" );
document.write( "a) what is the probability that none will ever be solved<BR>\n" );
document.write( "0.8^6 = 0.2621<BR>\n" );
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document.write( "b) probability at least one will be solved<BR>\n" );
document.write( "P(at least one solved) = 1 - P(none solved) = 1-0.2621 = 0.737856...<BR>\n" );
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document.write( "c) expected # of crimes that will be solved and what is the standard deviation<BR>\n" );
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document.write( "Expected number = np<BR>\n" );
document.write( "Expected number = 6*0.8 = 4.8<BR>\n" );
document.write( "Std = sqrt(6*0.8*0.2) = 0.9798<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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