document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1197973>Question 1197973</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A small company involved in​ e-commerce is interested in statistics concerning the use of​ e-mail. A poll found that 39​% of a random sample of  ​1076 adults, who use a computer at their​ home, work, or​ school, said they do not send or receive​ e-mail. Complete parts a through e.<BR>\n" );
document.write( " Find the margin of error for this poll if we want ​95% confidence in our estimate of the percent of American adults who do not use​ e-mail.<BR>\n" );
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document.write( "Find that margin of error in 99% confidence<BR>\n" );
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document.write( "At 95% confidence, the z critical value is roughly z = 1.96<BR>\n" );
document.write( "Use a table like this<BR>\n" );
document.write( "<a  rel=nofollow HREF= \"https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf\">https://www.sjsu.edu/faculty/gerstman/StatPrimer/t-table.pdf</a><BR>\n" );
document.write( "to get that value. Look at the bottom row labeled \"Z\" and above the 95% confidence level.\r<BR>\n" );
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document.write( "phat = sample proportion<BR>\n" );
document.write( "phat = 0.39<BR>\n" );
document.write( "n = sample size<BR>\n" );
document.write( "n = 1076\r<BR>\n" );
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document.write( "E = margin of error for a proportion<BR>\n" );
document.write( "E = z*sqrt(phat*(1-phat)/n)<BR>\n" );
document.write( "E = 1.96*sqrt(0.39*(1-0.39)/1076)<BR>\n" );
document.write( "E = 0.02914386568497<BR>\n" );
document.write( "E = 0.029<BR>\n" );
document.write( "The margin of error is roughly 0.029 for the 95% confidence interval estimating the population proportion (p).\r<BR>\n" );
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document.write( "For the 99% confidence interval, we'll repeat the same outline of steps. <BR>\n" );
document.write( "However, this time we'll use z = 2.576 which is found in the table linked above. <BR>\n" );
document.write( "The other values remain the same.<BR>\n" );
document.write( "E = z*sqrt(phat*(1-phat)/n)<BR>\n" );
document.write( "E = 2.576*sqrt(0.39*(1-0.39)/1076)<BR>\n" );
document.write( "E = 0.0383033663288<BR>\n" );
document.write( "E = 0.038\r<BR>\n" );
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document.write( "Answers:<BR>\n" );
document.write( "Margin of error at 95% confidence = <font color=red>0.029</font><BR>\n" );
document.write( "Margin of error at 99% confidence = <font color=red>0.038</font><BR>\n" );
document.write( "Round the values however instructed.<BR>\n" );
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