document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=601345>Question 601345</A>: <I><SPAN STYLE=\"word-break: break-all;\">  a 95% confidence interval for a population mean was reported to be 152 to 160. if standard deviation is 15, what sample size was used in this study? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #379694 by </B><A HREF=/tutors/aboutme.mpl?userid=flame8855><B>flame8855(424)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=flame8855><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=flame8855><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=379694\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> lets calculate the mean : <BR>\n" );
document.write( "mean = 152+160/2= 156<BR>\n" );
document.write( "lets take one of the extremity<BR>\n" );
document.write( "160=156 +1.96(15)/sqrt(n)<BR>\n" );
document.write( "4=29.40/sqrt(n)<BR>\n" );
document.write( "n= 54.02\r<BR>\n" );
document.write( "\n" );
document.write( "So the sample size is about 54<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );