document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1133557>Question 1133557</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Proctor & Gamble claims that at least half the bars of Ivory soap they produce are 99.44% pure (or more pure) as advertised. Unilever, one of Proctor & Gamble's competitors, wishes to put this claim to the test. They sample the purity of 112 bars of Ivory soap. They find that 44 of them meet the 99.44% purity advertised.\r<BR>\n" );
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document.write( "1. Multiple choice: What type of test should be run?\r<BR>\n" );
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document.write( "(a) t-test of a mean<BR>\n" );
document.write( "(b) z-test of a proportion\r<BR>\n" );
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document.write( "2. Multiple choice: The alternative hypothesis indicates a\r<BR>\n" );
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document.write( "(a) right-tailed test<BR>\n" );
document.write( "(b) two-tailed test<BR>\n" );
document.write( "(c) left-tailed test\r<BR>\n" );
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document.write( "3. Calculate the p-value: __________ \r<BR>\n" );
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document.write( "4. Multiple choice: Does Unilever have sufficient evidence to reject Proctor & Gamble's claim?\r<BR>\n" );
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document.write( "(a) Yes<BR>\n" );
document.write( "(b) No </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #750853 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=750853\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a one sample proportion test<BR>\n" );
document.write( "Ho: purity is in 0.5 of them or more<BR>\n" );
document.write( "Ha: purity is not in 0.5 of them\r<BR>\n" );
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document.write( "left tailed test with 5% (if this is desired) at z<=-1.645<BR>\n" );
document.write( "44/112 is 0.393<BR>\n" );
document.write( "z=(0.393-0.5)/sqrt (0.393*0.607/112)<BR>\n" );
document.write( "=-.107/0.0462<BR>\n" );
document.write( "=-2.32<BR>\n" );
document.write( "p=0.010<BR>\n" );
document.write( "Yes, there is sufficient evidence to reject the claim even at the 1% level.<BR>\n" );
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