document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=138258>Question 138258</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello again, need assistance please!!  THANKS A BUNCH - UR a LIFESAVER!!\r<BR>\n" );
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document.write( "1. A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were:<BR>\n" );
document.write( "3.087,	3.131, 3.241,    3.241,   3.270,   3.353,   3.400,   3.411,  3.437,    3.477\r<BR>\n" );
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document.write( "(a) Construct a 90 percent confidence interval for the true mean weight. <BR>\n" );
document.write( "(b) What sample size would be necessary to estimate the true weight with an error of ± 0.03 grams with 90 percent confidence?<BR>\n" );
document.write( "(c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during manufacture. (Data are from a project by MBA student Henry Scussel.)\r<BR>\n" );
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document.write( "2. In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 1,143 were positive.<BR>\n" );
document.write( "(a) Construct a 95 percent confidence interval for the population proportion of positive drug tests. <BR>\n" );
document.write( "(b) Why is the normality assumption not a problem, despite the very small value of p?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #100965 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=100965\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1. A random sample of 10 miniature Tootsie Rolls was taken from a bag. Each piece was weighed on a very accurate scale. The results in grams were:<BR>\n" );
document.write( "3.087, 3.131, 3.241, 3.241, 3.270, 3.353, 3.400, 3.411, 3.437, 3.477 <BR>\n" );
document.write( "(a) Construct a 90 percent confidence interval for the true mean weight. <BR>\n" );
document.write( "(b) What sample size would be necessary to estimate the true weight with an error of ± 0.03 grams with 90 percent confidence?<BR>\n" );
document.write( "(c) Discuss the factors which might cause variation in the weight of Tootsie Rolls during manufacture. (Data are from a project by MBA student Henry Scussel.) <BR>\n" );
document.write( "Go to www.algebra.com and search for 136270<BR>\n" );
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document.write( "2. In 1992, the FAA conducted 86,991 pre-employment drug tests on job applicants who were to be engaged in safety and security-related jobs, and found that 1,143 were positive.<BR>\n" );
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document.write( "p-hat = 1143/86991 = 0.01314...<BR>\n" );
document.write( "(a) Construct a 95 percent confidence interval for the population proportion of positive drug tests. <BR>\n" );
document.write( "E = 1.96*sqrt[0.01314*(1-0.01314)/86,991] = 0.0007567..<BR>\n" );
document.write( "95% CI: 0.79615 , 83671<BR>\n" );
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document.write( "(b) Why is the normality assumption not a problem, despite the very small value of p? <BR>\n" );
document.write( "The sample is random<BR>\n" );
document.write( "The sample size is less than 10% of the population<BR>\n" );
document.write( "etc.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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