document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=478722>Question 478722</A>: <I><SPAN STYLE=\"word-break: break-all;\"> (8.46) A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were\r<BR>\n" );
document.write( "\n" );
document.write( "3.18<BR>\n" );
document.write( "3.21<BR>\n" );
document.write( "3.15<BR>\n" );
document.write( "3.42<BR>\n" );
document.write( "3.23<BR>\n" );
document.write( "3.36<BR>\n" );
document.write( "3.47<BR>\n" );
document.write( "3.29<BR>\n" );
document.write( "3.37<BR>\n" );
document.write( "3.40\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "(a)	Construct a 95 percent confidence interval for the true mean weight. \r<BR>\n" );
document.write( "\n" );
document.write( "(b) What sample size would be necessary to estimate the true weight with an error of ± 0.01 grams with 99 percent confidence? (Hint: Use sample size calculation for means.)\r<BR>\n" );
document.write( "\n" );
document.write( "(c) What factors might cause variation in the weight of Tootsie Rolls during manufacture? <BR>\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 #328044 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=328044\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 3.18<BR>\n" );
document.write( "3.21<BR>\n" );
document.write( "3.15<BR>\n" );
document.write( "3.42<BR>\n" );
document.write( "3.23<BR>\n" );
document.write( "3.36<BR>\n" );
document.write( "3.47<BR>\n" );
document.write( "3.29<BR>\n" );
document.write( "3.37<BR>\n" );
document.write( "3.40 \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "I used a TI-84 on the data to get the following:<BR>\n" );
document.write( "(a) Construct a 95 percent confidence interval for the true mean weight.<BR>\n" );
document.write( "T-interval: 3.2285 < p < 3.3875<BR>\n" );
document.write( "---------------------------<BR>\n" );
document.write( "(b) What sample size would be necessary to estimate the true weight with an error of ± 0.01 grams with 99 percent confidence? (Hint: Use sample size calculation for means.)<BR>\n" );
document.write( "---<BR>\n" );
document.write( "n = [z*s/E]^2 = [2.58*0.105/0.01]^2 = 734 when rounded up<BR>\n" );
document.write( "=======================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );