document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=418768>Question 418768</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Carbon monoxide (CO) emissions for a certain kind of car vary with mean 2,9g/mi and standard deviation 0.4g/m. A company has 80 of these cars in its fleet. Let -y (the - is supposed to be over y) represent the mean CO level for the company's fleet. \r<BR>\n" );
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document.write( "a) What's the approximate model for the distribution of -y (the - is supposed to be over the y)? Explain.\r<BR>\n" );
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document.write( "b) Estimate the probability that -y (he - is supposed to be over the y) is between 3.0 and 3.1g/mi.\r<BR>\n" );
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document.write( "c) There is only a 5% chance that the fleet's mean CO level is greater what value?\r<BR>\n" );
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document.write( "THANKS </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #293004 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=293004\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Carbon monoxide (CO) emissions for a certain kind of car vary with mean 2,9g/mi and standard deviation 0.4g/m. <BR>\n" );
document.write( "A company has 80 of these cars in its fleet. <BR>\n" );
document.write( "Let -y (the - is supposed to be over y) represent the mean CO level for the company's fleet. <BR>\n" );
document.write( "a) What's the approximate model for the distribution of -y (the - is supposed to be over the y)? Explain.<BR>\n" );
document.write( "mean of y-bar = mean of y = 2.9g/mi<BR>\n" );
document.write( "std of y-bar = 0.4/sqrt(80)<BR>\n" );
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document.write( "b) Estimate the probability that -y (he - is supposed to be over the y) is between 3.0 and 3.1g/mi.<BR>\n" );
document.write( "t(3) = (3-2.9)/[0.4/sqrt(80)] = 2.2361<BR>\n" );
document.write( "t(3.1) = (3.1-2.9)/[0.4/sqrt(80)] = 4.4722<BR>\n" );
document.write( "P(3<= y-bar <=3.1) = P(2.2361<= t <= 4.4722 when df = 79) = 0.0141<BR>\n" );
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document.write( "c) There is only a 5% chance that the fleet's mean CO level is greater what value?<BR>\n" );
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document.write( "Find the t-value with a right tail of 5% when df = 79<BR>\n" );
document.write( "invT(0.95,79) = 1.6644<BR>\n" );
document.write( "Find the corresponding y-bar value using y-bar = ts+u<BR>\n" );
document.write( "y-bar = 1.6644+2.9 = 2.9744<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "========== <BR>\n" );
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