document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=187925>Question 187925</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 2.	A coin was flipped 80 times and came up tails 54 times. At the 0.05 level of significance, is the coin biased toward tails? Show your decision rule and calculations.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #140912 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=140912\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A coin was flipped 80 times and came up tails 54 times. At the 0.05 level of significance, is the coin biased toward tails? Show your decision rule and calculations.<BR>\n" );
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document.write( "Ho: p = 1/2<BR>\n" );
document.write( "Ha: p > 1/2<BR>\n" );
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document.write( "sample proportion: 54/80 = 0.675<BR>\n" );
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document.write( "test statistic: z(0.675) = (0.675-0.5)/sqrt((1/2)(1/2)/80) =  3.1305<BR>\n" );
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document.write( "Critical value for right-tail test with alpha=5%: z=-1.96 or z=1.96<BR>\n" );
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document.write( "p-value = 2(P(z>1.96)) = 2(0.000873) = 0.0017<BR>\n" );
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document.write( "Decision Rule: If p-value is less than 5%, reject Ho.<BR>\n" );
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document.write( "Conclusion: Since p-value is less than 5%, reject Ho ; the cois is<BR>\n" );
document.write( "biased toward heads.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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