document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=756402>Question 756402</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The length of country and western songs is normally distributed and has a mean of 200 seconds and a standard deviation of 30 seconds. Find the probability that a random selection of 9 songs will have mean length of 186.30 seconds or less. Assume the distribution of the lengths of the songs is normal </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #460176 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=460176\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The length of country and western songs is normally distributed and has a mean of 200 seconds and a standard deviation of 30 seconds. Find the probability that a random selection of 9 songs will have mean length of 186.30 seconds or less. Assume the distribution of the lengths of the songs is normal<BR>\n" );
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document.write( "t(186.3) = (186.3-200)/[30/sqrt(9)] = -1.3700<BR>\n" );
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document.write( "P(x < 186.3) = P(t < -1.3700,when df = 8) = tcdf(-100,-1.37,8) = 0.1039<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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