document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=204459>Question 204459</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study,<BR>\n" );
document.write( "researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age<BR>\n" );
document.write( "58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the<BR>\n" );
document.write( "inactive pill. (a) State the appropriate hypotheses. (b) Obtain a test statistic and p-value. Interpret<BR>\n" );
document.write( "the results at &#945; = .01. (c) Is normality assured? (d) Is the difference large enough to be important?<BR>\n" );
document.write( "(e) What else would medical researchers need to know before prescribing this drug widely? (Data<BR>\n" );
document.write( "are from Science News 153 [May 30, 1998], p. 343.)<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #154385 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=154385\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Does lovastatin (a cholesterol-lowering drug) reduce the risk of heart attack? In a Texas study,<BR>\n" );
document.write( "researchers gave lovastatin to 2,325 people and an inactive substitute to 2,081 people (average age 58). After 5 years, 57 of the lovastatin group had suffered a heart attack, compared with 97 for the inactive pill. <BR>\n" );
document.write( "(a) State the appropriate hypotheses.<BR>\n" );
document.write( "Ho: p(placebo)-P(lova) = 0<BR>\n" );
document.write( "Ha: p(placebo)-p(lova) > 0 <BR>\n" );
document.write( "(b) Obtain a test statistic and p-value. Interpret<BR>\n" );
document.write( "the results at &#945; = .01<BR>\n" );
document.write( "I ran a two-proportion z-test and got the following.<BR>\n" );
document.write( "Test statistic: z = 3.987<BR>\n" );
document.write( "p-value: 0.00003348....<BR>\n" );
document.write( "Conclusion: Since the p-value is less than 1% reject Ho.<BR>\n" );
document.write( "Less than 0.003348% of test results could have provided stronger <BR>\n" );
document.write( "proof for rejecting Ho.<BR>\n" );
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document.write( " <BR>\n" );
document.write( "(c) Is normality assured?<BR>\n" );
document.write( "I'll leave that to you.<BR>\n" );
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document.write( "(d) Is the difference large enough to be important?<BR>\n" );
document.write( "Yes it is very large as seen in the very small p-value.<BR>\n" );
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document.write( "(e) What else would medical researchers need to know before prescribing this drug widely?<BR>\n" );
document.write( "I'll leave that to you.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );