document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1140893>Question 1140893</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a class in which the final course grade depends entirely on the average of four equally weighted 100-point tests, Paul has scored 82, 88, and 87 on the first three.  What range of scores on the fourth test will give Paul a C for the semester (an average between 70 and 79, inclusive)? Assume that all test scores have a non-negative value.  \r<BR>\n" );
document.write( "\n" );
document.write( "**Express your answer in interval notation**   </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #761430 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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/cgi-bin/show-face.mpl?user=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=761430\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4%2A70%3C=%2882%2B88%2B87%2Bx%29%3C=4%2A79 ALIGN=MIDDLE  ALT=\"4%2A70%3C=%2882%2B88%2B87%2Bx%29%3C=4%2A79\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=280%3C=257%2Bx%3C=316 ALIGN=MIDDLE  ALT=\"280%3C=257%2Bx%3C=316\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=23%3C=x%3C=59 ALIGN=MIDDLE  ALT=\"23%3C=x%3C=59\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
document.write( "ANSWER: [23,59]<br><BR>\n" );
document.write( "Note the stated condition for getting a C is probably not correct.  The statement says a C grade means an average in the interval [70,79]; probably the correct interval for getting a C grade is [70,80).<br><BR>\n" );
document.write( "That will of course change the answer to the problem slightly. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );