document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1202944>Question 1202944</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The mean amount of time it takes a kidney stone to pass is 12 days and the standard deviation is 4 days. Suppose that one individual is randomly chosen. Let X = time to pass the kidney stone. Round all answers to 4 decimal places where possible.\r<BR>\n" );
document.write( "\n" );
document.write( "What is the minimum number of days for the upper quarter of the time to pass a kidney stone ?\r<BR>\n" );
document.write( "\n" );
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 #838166 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52781)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=838166\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "The mean amount of time it takes a kidney stone to pass is 12 days <BR>\n" );
document.write( "and the standard deviation is 4 days. Suppose that one individual is randomly chosen. <BR>\n" );
document.write( "Let X = time to pass the kidney stone. Round all answers to 4 decimal places where possible.<BR>\n" );
document.write( "What is the minimum number of days for the upper quarter of the time to pass a kidney stone ?<BR>\n" );
document.write( "~~~~~~~~~~~~~~~~~~~\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "A normal curve is a bell-shaped.\r\n" );
document.write( "\r\n" );
document.write( "In this problem, they want you determine a raw mark x on the time axis \r\n" );
document.write( "such that the area under the given normal curve on the right of this mark is 1/4.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "It is the same as to find a raw mark x on the time axis \r\n" );
document.write( "such that the area under the given normal curve on the left of this mark is 3/4, or 0.75.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "For this purpose, you may use the standard function invNorm in your regular calculator \r\n" );
document.write( "TI-83 or TI-84\r\n" );
document.write( "\r\n" );
document.write( "                area  mean SD    <<<---===  formatting pattern.  \r\n" );
document.write( "    P = invNorm(0.75,  12, 4).\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "It gives the <U>ANSWER</U>  P = 14.698\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "In my opinion, the request (the instruction in the post) to provide an answer with \r\n" );
document.write( "4 decimal places is non-sensical and shows absence of  common sense.  \r\n" );
document.write( "In such problems, one decimal place is enough.\r\n" );
document.write( "</PRE>\r<BR>\n" );
document.write( "\n" );
document.write( "Solved.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "------------------\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Alternatively, you may use an online free of charge calculator \r<BR>\n" );
document.write( "\n" );
document.write( "https://onlinestatbook.com/2/calculators/inverse_normal_dist.html\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "If you are a beginner student, I insistently recommend you to play with this online calculator.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "It has convenient, intuitively clear interface and shows the area of interest,<BR>\n" );
document.write( "so you quickly will learn the subject, the meaning and the technique of these calculations and will be happy.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );