document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1191438>Question 1191438</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the average shelf life of the mix is 216 days. After a revised mix has been developed, a sample of nine boxes of cake mix gave these shelf lives (in days): 215, 217, 218, 219, 216, 219, 217, 220 and 218. At the 0.025 level, has the shelf life of the cake mix increased?<BR>\n" );
document.write( "A. No, because computed t lies in the region of acceptance.<BR>\n" );
document.write( "B. No, because 217.24 is quite close to 216.<BR>\n" );
document.write( "C. Yes, because computed t is greater than the critical value.<BR>\n" );
document.write( "D. Yes, because computed t is less than the critical value. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #823558 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=823558\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> mean is 217.67<BR>\n" );
document.write( "s=1.58<BR>\n" );
document.write( "assuming sd of sample is unbiased estimator of pop.<BR>\n" );
document.write( "use 1 way test here if expected to increase. Critical value is t>2.306<BR>\n" );
document.write( "t=(217.67-216)/1.58/sqrt(9)<BR>\n" );
document.write( "=1.67*3/1.58<BR>\n" );
document.write( "=3.17<BR>\n" );
document.write( "Yes, because computed t is > critical value<BR>\n" );
document.write( " </SPAN>\n" );
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