document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1102481>Question 1102481</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Question 10<BR>\n" );
document.write( "Jennifer Cantu, Vice President of Customer Services at Tri-State Auto Insurance Inc.,<BR>\n" );
document.write( "monitors the claims processing time of the claims division. Each week, her staff randomly<BR>\n" );
document.write( "selects a sample of 64 claims. They test the null hypothesis that the \"mean processing time<BR>\n" );
document.write( "is 5 days\" and the alternative hypothesis that the \"mean processing time is more than 5<BR>\n" );
document.write( "days\" using the 0.05 level of significance. Last week the sample mean was 5.2 days.<BR>\n" );
document.write( "Assuming a population standard deviation of 1.56 days, the appropriate decision is _____.\r<BR>\n" );
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document.write( "Answers: <BR>\n" );
document.write( "a.<BR>\n" );
document.write( "reduce the sample size<BR>\n" );
document.write( "b.<BR>\n" );
document.write( "do not reject the null hypothesis<BR>\n" );
document.write( "c.<BR>\n" );
document.write( "increase the sample size<BR>\n" );
document.write( "d.<BR>\n" );
document.write( "reject the null hypothesis<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 #717195 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=717195\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> At the 0.05 level of significance, <BR>\n" );
document.write( "test statistic is z=(xbar-mean)/sigma/sqrt(n)=(5.2-5)/1.56/sqrt (64)<BR>\n" );
document.write( "This is z=0.2*8/1.56=1.03.  This has a p-value of 0.15 which is greater than alpha of 0.05, so fail to reject Ho and b. is the answer.\r<BR>\n" );
document.write( "<BR>\n" );
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document.write( "If one uses a two-sided test, the 95% CI half interval is 1.96*1.56/8, z*sigma/sqrt(n), using a z test because the population sd is used.  That half-interval is 0.38, so the 95% CI is [4.82, 5.58].<BR>\n" );
document.write( "The appropriate decisions is b., do not reject Ho.  The 95% CI contains the null hypothesis, and that means the null hypothesis is not rejected. </SPAN>\n" );
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