document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=139808>Question 139808</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Stan you answered this question but my instructor came back with another question.  Here is the orginal question. The number of admissions for Carolinas Medical Center hospital emergency room over the course of a lunar cycle was 129 patients per 36 days per full moon as compared to 1,315 patients per 330 days per nonfull moon days \r<BR>\n" );
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document.write( "Perform a chi-square test on the data. Use the test to prove (or disprove) that hospital emergency room admissions are dependent (or independent) on (of) the full moon lunar phase.\r<BR>\n" );
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document.write( "Full moons were defined as three-day periods in the 29.531-day lunar cycle, with the middle day being described in the world almanac as the full moon.<BR>\n" );
document.write( ": The number of admissions for Carolinas Medical Center hospital emergency room over the course of a lunar cycle was 129 patients per 36 days per full moon as compared to 1,315 patients per 330 days per nonfull moon days.  \r<BR>\n" );
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document.write( "Here is the question my instrutor asked....How did you get the test statistics, I'm sure your classmates are curious of how the .0287 generated as well as the p-value of .5920.  Help.\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 #101908 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=101908\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Ho: full-moon and # of patients are independent<BR>\n" );
document.write( "Ha: they are dependent<BR>\n" );
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document.write( "I set up 2 rows of DATA in a matrix on a TI caluculator:<BR>\n" );
document.write( "full-moon.....129......36<BR>\n" );
document.write( "no full-m....1315......330<BR>\n" );
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document.write( "I ran a Chi-Sq Test on the matrix and got:<BR>\n" );
document.write( "test statistic: Chi-Sq = 0.87089...<BR>\n" );
document.write( "p-value = 0.59209..<BR>\n" );
document.write( "df = (2-1)(2-1)<BR>\n" );
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document.write( "You could do this by hand:<BR>\n" );
document.write( "The data listed above is the \"Observed\" data.<BR>\n" );
document.write( "You could generate the \"Expected data\"; that is the numbers you would<BR>\n" );
document.write( "expect to see if the # of patients was independent of the full-moon.<BR>\n" );
document.write( "That matrix would be:<BR>\n" );
document.write( "full-moon.....131.64......33.365<BR>\n" );
document.write( "no full-m.....1312.4......332.64<BR>\n" );
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document.write( "Then you would have to calculate the Chi-Sq statistic<BR>\n" );
document.write( "using: <BR>\n" );
document.write( "Chi-Sq = Sum[ (observed-expected)^2/expected] for each of the 4 entry <BR>\n" );
document.write( "positions.<BR>\n" );
document.write( "Then you would have to use your Chi-Sq chart to calculate the area<BR>\n" );
document.write( "to the right of your test statistic to get the p-value.<BR>\n" );
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document.write( "I don't know how much evidence your instructor requires. The <BR>\n" );
document.write( "calculator is handy as it does all the arithmetic.  However,<BR>\n" );
document.write( "you should try to understand what is behind the numbers the <BR>\n" );
document.write( "calculator generates.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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