document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1166037>Question 1166037</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A large flashlight is powered by 5 batteries. Suppose that the life of a battery is normally distributed with mean 150 and standard deviation 15. The flashlight will cease functioning if one or more of its batteries go dead. Assuming the lives of batteries are independent. What is the probability that flashlight will operate more than 130 hours? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #790590 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=790590\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> So what is the probability all 5 batteries will last more than 130 hours?<BR>\n" );
document.write( "the probability of one is z=(x-mean)/sd or z>(130-150)/15 or z> -1.33 <BR>\n" );
document.write( "this has probability of 0.9082<BR>\n" );
document.write( "for all 5 batteries to do this would be 0.9082^5=0.6179.<BR>\n" );
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