document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1185353>Question 1185353</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The time taken to install a new telephone is found to be normally distributed with a mean time equal to 45 minutes and a standard deviation of 8 minutes.  For a new installation,  what is the probability that <BR>\n" );
document.write( "1. it will take more than 51 minutes<BR>\n" );
document.write( "2. It will take less than 45 minutes  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #816276 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=816276\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> you can use the following normal distribution z-score calculator to solve this easily.\r<BR>\n" );
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document.write( "<a  rel=nofollow HREF= \"https://davidmlane.com/hyperstat/z_table.html\" target = \"_blank\">https://davidmlane.com/hyperstat/z_table.html</a>\r<BR>\n" );
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document.write( "the first one gives you the probability it will take more than 51 minutes.\r<BR>\n" );
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document.write( "the second one gives you  the probability it will take less than 45 minutes.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2021/100202.jpg\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2021/100203.jpg\" >\r<BR>\n" );
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document.write( "this calculator can be used with z-scores and with raw scores.\r<BR>\n" );
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document.write( "with z-scores, the mean is 0 and the standard deviation is 1.\r<BR>\n" );
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document.write( "with raw scores, the mean and the standard deviation are what they are as given in the problem.\r<BR>\n" );
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document.write( "when you are dealing with sample means in samples whose size is greater than 1, then you need to use the standard error, rather than the standard deviation.\r<BR>\n" );
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document.write( "this problem did not require that.<BR>\n" );
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