document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=756218>Question 756218</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I really need help on this. Thanks so much. I would really appreciate it. \r<BR>\n" );
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document.write( "Final averages are typically approximately normally distributed with a mean of 78 and a standard deviation of 11. Your professor says that the top 6% of the class will receive an A; the next 24%, a B; the next 41%, a C; the next 18%, a D; and the bottom 11%, an F. (Give your answers correct to one decimal place.)\r<BR>\n" );
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document.write( "(a) What average must you exceed to obtain an A?\r<BR>\n" );
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document.write( "(b) What average must you exceed to receive a grade of C or better?\r<BR>\n" );
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document.write( "(c) What average must you obtain to pass the course? (You'll need a D or better.)\r<BR>\n" );
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document.write( "You may need to use the appropriate table in Appendix B to answer this question.<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 #460044 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=460044\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Final averages are typically approximately normally distributed with a mean of 78 and a standard deviation of 11. Your professor says that the top 6% of the class will receive an A; the next 24%, a B; the next 41%, a C; the next 18%, a D; and the bottom 11%, an F. (Give your answers correct to one decimal place.)<BR>\n" );
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document.write( "Using a TI-84 to get these answers.<BR>\n" );
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document.write( "(a) What average must you exceed to obtain an A?<BR>\n" );
document.write( "Find the z-value with a left-tail of 94%<BR>\n" );
document.write( "invNorm(0.94) = 1.5548<BR>\n" );
document.write( "Using the formula z = (x-u)/s to solve for \"x\"<BR>\n" );
document.write( "you get x = z*s+u<BR>\n" );
document.write( "x is the score; z, s, and u you now know.<BR>\n" );
document.write( "So solve for \"x\":<BR>\n" );
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document.write( "score = 1.5548*11+78 = 95.1<BR>\n" );
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document.write( "(b) What average must you exceed to receive a grade of C or better?<BR>\n" );
document.write( "invNorm(0.29) = -0.5534<BR>\n" );
document.write( "score = -9.5534*11+78 = 71.91<BR>\n" );
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document.write( "(c) What average must you obtain to pass the course? (You'll need a D or better.)<BR>\n" );
document.write( "invNorm(-.11) = -1.2265<BR>\n" );
document.write( "score = -1.2265*11+78 = 64.51<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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