document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=149621>Question 149621</A>: <I><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 &#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<BR>\n" );
document.write( "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( "Correct?             Regular Cola     Diet Cola           Row Total<BR>\n" );
document.write( "Yes, got it right                                                                                                      7          7                  14<BR>\n" );
document.write( "No, got it wrong                                                                                                      12        20                  32<BR>\n" );
document.write( "Col Total                                                                                                      19         27                 46 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #110045 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=110045\">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.<BR>\n" );
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document.write( "Research question: At &#945; = .05, is the correctness of the prediction different for the two types of cola drinkers? <BR>\n" );
document.write( "Could you identify your favorite brand in this kind of test?<BR>\n" );
document.write( "Chi-Square Test:<BR>\n" );
document.write( "Ho: Cola type and quessing results are homogeneous (the same for both Colas)<BR>\n" );
document.write( "Ha: Results are not homogeneous<BR>\n" );
document.write( "Ran a Chi-Square on the 2 x 2 with the following results:<BR>\n" );
document.write( "Test statistic: 0.62768...<BR>\n" );
document.write( "p-value: 0.428...<BR>\n" );
document.write( "Conclusion: Since the p-value is greater than 5%, fail to reject Ho.<BR>\n" );
document.write( "Results are the same for both solas.<BR>\n" );
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document.write( "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 z^2 is the same as your chi-square statistic.<BR>\n" );
document.write( "Which test do you prefer? Why? (Data are from Consumer Reports 56, no. 8 [August 1991], p. 519.)<BR>\n" );
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document.write( "Ran a 2-sample z-Test:<BR>\n" );
document.write( "Ho: u1=u2<BR>\n" );
document.write( "Ha: u1 is not equal to u2<BR>\n" );
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document.write( "test statistic: z = -0.72428596...<BR>\n" );
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document.write( "Does z^2 = the Chi-Sq<BR>\n" );
document.write( "(-0.72428596..)^2 ? 0.62768...<BR>\n" );
document.write( "Not quite.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( "Correct?........... Regular Cola Diet Cola Row Total<BR>\n" );
document.write( "Yes, got it right...... 7............ 7...... 14<BR>\n" );
document.write( "No, got it wrong....... 12.......... 20...... 32<BR>\n" );
document.write( "Col Total.............. 19.......... 27...... 46<BR>\n" );
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