document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=265552>Question 265552</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am having a difficult time understanding this problem. Can someone please help?\r<BR>\n" );
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document.write( "A researcher is interested in estimating the proportion of voters who favor a tax on e-commerce.  In a sample of 250 people she finds that 36 favor such a tax.  \r<BR>\n" );
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document.write( "a.  Find a 95% confidence interval for the true population proportion of voters who favor such a tax.<BR>\n" );
document.write( "b.  Find a 99% confidence interval for the true population proportion of voters who favor such a tax.  <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 #195241 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=195241\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I am having a difficult time understanding this problem. Can someone please help? <BR>\n" );
document.write( "A researcher is interested in estimating the proportion of voters who favor a tax on e-commerce. In a sample of 250 people she finds that 36 favor such a tax.<BR>\n" );
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document.write( "In favor of:<BR>\n" );
document.write( "sample proportion = phat = 36/250 = 0.144<BR>\n" );
document.write( "standard error = invNorm(0.975)*sqrt[0.144*0.856/250] = 0.0435..<BR>\n" );
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document.write( "a. Find a 95% confidence interval for the true population proportion of voters who favor such a tax.<BR>\n" );
document.write( "95% CI : 0.144-0.0435 < p < 0.144  + 0.0435<BR>\n" );
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document.write( "b. Find a 99% confidence interval for the true population proportion of voters who favor such a tax.<BR>\n" );
document.write( "sample proportion = 0.144<BR>\n" );
document.write( "standard error = invNorm(0.995)*sqrt(0.144*0.856/250] = 0.0572<BR>\n" );
document.write( "99% CI : 0.144 - 0.0572 < p < 0.144 + 0.0572<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
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