document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1170606>Question 1170606</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Suppose that the times required for a cable company to fix cable problems in its customers' homes are normally distributed with mean 45 minutes and standard deviation 15 minutes.  <BR>\n" );
document.write( "a)What is the probability that a randomly selected cable repair visit will take at least 36 minutes? <BR>\n" );
document.write( "b)What is the probability that a randomly selected cable repair visit will take at most 60 minutes? <BR>\n" );
document.write( "c)What is the probability that a randomly selected cable repair visit will take between 36 minutes and 60 minutes? <BR>\n" );
document.write( "d)5% of the cable repair visits will require more than what time? <BR>\n" );
document.write( "e)What is the probability that the mean tame for 25 visits will be more than 50 minutes?<BR>\n" );
document.write( "What is the probability that the mean tame for 36 visits will be more than 50 minutes\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #795459 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=795459\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> z=(x-mean)/sd<BR>\n" );
document.write( "a. z is > (36-45)/15 or -0.6, prob. 0.7257<BR>\n" );
document.write( "b. at most 60 minutes is z < 15/15 or 1, probability 0.8413.<BR>\n" );
document.write( "c. between the two is -0.6 < z < 1, with probability 0.5671<BR>\n" );
document.write( "d. z is 1.645 for the 95th percentile, so x-mean=24.675 and x=69.675 min.  More than that.<BR>\n" );
document.write( "e. this is z > (50-45)/15/sqrt(25) or z>1.6  with probability 0.0548<BR>\n" );
document.write( "f. this is z > 5/15/sqrt(36) or z>2 with probability 0.0228 </SPAN>\n" );
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