document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1060560>Question 1060560</A>: <I><SPAN STYLE=\"word-break: break-all;\"> you want to estimate p= the true proportion of students at your school who have their drivers license. Which of the following is the smallest number of students that should be surveyed to estimate p with a margin of error of no more than .05 with 90% confidence? <BR>\n" );
document.write( "A. 300<BR>\n" );
document.write( "B. 275<BR>\n" );
document.write( "C. 250<BR>\n" );
document.write( "D. 225<BR>\n" );
document.write( "E. 200<BR>\n" );
document.write( "I know the answer is B but I have no idea how to get to that answer.<BR>\n" );
document.write( "Ive tried using the Margin of Error formula and solving for N but I'm 59.04 as an answer for N. </SPAN>\n" );
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document.write( "you want to estimate p= the true proportion of students at your school who have their drivers license. Which of the following is the smallest number of students that should be surveyed to estimate p with a margin of error of no more than .05 with 90% confidence? <BR>\n" );
document.write( "A. 300<BR>\n" );
document.write( "B. 275<BR>\n" );
document.write( "C. 250<BR>\n" );
document.write( "D. 225<BR>\n" );
document.write( "E. 200<BR>\n" );
document.write( "I know the answer is B but I have no idea how to get to that answer.<BR>\n" );
document.write( "Ive tried using the Margin of Error formula and solving for N but I'm 59.04 as an answer for N.<BR>\n" );
document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">I'm coming up with a MINIMUM sample size of 270.603, which when rounded up, becomes: 271. The SAMPLE PROPORTION closest to this is 275 <b>(CHOICE B).</b><BR>\n" );
document.write( "The ESTIMATED SAMPLE PROPORTION was calculated using the following formula: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=matrix%281%2C5%2C+n%2C+%22=%22%2C+%28p-hat%29+%2A+%28q-hat%29%2C+%22%2A%22%2C+%28Z%5Bc%5D%2FE%29%5E2%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Now, since NO PRELIMINARY ESTIMATE WAS GIVEN/WAS AVAILABLE, then .5(50%) should be used for p-hat, or for the ASSUMED proportion<BR>\n" );
document.write( "With p-hat being .5, q-hat = 1 - p-hat = 1 - .5 = .5<BR>\n" );
document.write( "Since this is a 90% CONFIDENCE INTERVAL, then significance level is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=matrix%281%2C3%2C+.1%2F2%2C+or%2C+.05%29 ALIGN=MIDDLE  ALT=\"matrix%281%2C3%2C+.1%2F2%2C+or%2C+.05%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and so, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Z%5Bcritical%5D+=+1.645 ALIGN=MIDDLE  ALT=\"Z%5Bcritical%5D+=+1.645\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "E (Margin of Error) = .05<BR>\n" );
document.write( "Therefore, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=matrix%281%2C5%2C+n%2C+%22=%22%2C+%28p-hat%29+%2A+%28q-hat%29%2C+%22%2A%22%2C+%28Z%5Bc%5D%2FE%29%5E2%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > becomes: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28matrix%281%2C16%2C+n%2C+%22=%22%2C+%28.5%29%28.5%29%2C+%22%2A%22%2C+%281.645%2F.05%29%5E2%2C+%22=%22%2C+.25%2A%2832.9%29%5E2%2C+%22=%22%2C+%22.25%281%2C082.41%29%22%2C+%22=%22%2C+270.6025%2C+%22%2C%22%2C+rounded%2C+up%2C+to%2C+highlight%28271%2C+students%29%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "In addition, when I used STATDISK to calculate the ESTIMATED SAMPLE PROPORTION, I got the same result: 271 students. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );