document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1102721>Question 1102721</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me answer these questions.\r<BR>\n" );
document.write( "\n" );
document.write( "1. For a certain urban area, it was found that in a sample of 6 months, an average of 31 burglaries occurred each month. The standard deviation was 4. find the 90% confidence interval of the true mean number of burglaries each month.\r<BR>\n" );
document.write( "\n" );
document.write( "2. A sample of 20 tuna showed that they swim an average of 8.6 miles per hour. The standard deviation for the sample was 1.6. find the 95% confidence interval of the true mean. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #717598 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=717598\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> CI is mean +/- t (df, value)*s/sqrt(n)<BR>\n" );
document.write( "for the first, it is 31 +/- t(df=31,0.95)*4/sqrt(31)<BR>\n" );
document.write( "This is 31 +/- (1.70*4/sqrt(31))<BR>\n" );
document.write( "That is 31+/-1.22<BR>\n" );
document.write( "(29.78, 32.22) burglaries<BR>\n" );
document.write( "=======================<BR>\n" );
document.write( "second is done same way<BR>\n" );
document.write( "CI is 8.6 +/-2.093*1.6/sqrt(20)<BR>\n" );
document.write( "=8.6+/-0.75<BR>\n" );
document.write( "(7.85, 9.35) speed in mph\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );