document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=136381>Question 136381</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 15.28 Can people really identify their favorite brand of cola? Volunteers tasted Coca-Cola Classic,Pepsi, Diet Coke, and Diet Pepsi, with the results shown below. Research question: At &#945; = .05, is the correctness of the prediction different for the two types of cola drinkers? Could you identify your favorite brand in this kind of test? Since it is a 2 × 2 table, try also a two-tailed two-sample z test for &#960;1 = &#960;2 (see Chapter 10) and verify that z2 is the same as your chi-square statistic.Which test do you prefer? Why? (Data are from Consumer Reports 56, no. 8 [August 1991], p. 519.)\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #99924 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=99924\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Can people really identify their favorite brand of cola? Volunteers tasted Coca-Cola Classic, Pepsi, Diet Coke, and Diet Pepsi, with the results shown below. Research question: At a = .05, is the correctness of the prediction different for the two types of cola drinkers? Since it is a 2 x 2 table, try also a two-tailed two-sample z test for &#960;1 = &#960;2 and verify that z² is the same as your chi-square statistic. <BR>\n" );
document.write( "Correct? Regular Diet Row Total<BR>\n" );
document.write( "Yes....... 7..... 7..... 14<BR>\n" );
document.write( "No....... 12.... 20..... 32<BR>\n" );
document.write( "Total.... 19.... 27..... 46<BR>\n" );
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document.write( "Ho: mu1=mu2<BR>\n" );
document.write( "Ha: mu1 is not equal to mu2<BR>\n" );
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document.write( "Chi-Sq:<BR>\n" );
document.write( "Test statistic: Chi-Sq = 0.62768...<BR>\n" );
document.write( "p-value: 0.4282 <BR>\n" );
document.write( "df=1<BR>\n" );
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document.write( "Conclusion: Fail to reject Ho because p-value > alpha.<BR>\n" );
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document.write( "2-Sample z-Test<BR>\n" );
document.write( "Test statistic: z=-1.4486<BR>\n" );
document.write( "p-value: 0.14746...<BR>\n" );
document.write( "Conclusion: Fail to reject Ho because p-value > alpha.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. \r<BR>\n" );
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