document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1176386>Question 1176386</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Consider the following grouped frequency distribution, which portrays the duration (in minutes) of 50 lectures<BR>\n" );
document.write( "delivered by a Chemistry professor.\r<BR>\n" );
document.write( "\n" );
document.write( "Duration (Minutes) Frequency<BR>\n" );
document.write( "30.00 < 40.00 3<BR>\n" );
document.write( "40.00 < 50.00 7<BR>\n" );
document.write( "50.00 < 60.00 18<BR>\n" );
document.write( "60.00 < 70.00 13<BR>\n" );
document.write( "70.00 < 80.00 8<BR>\n" );
document.write( "80.00 < 90.00 1\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Using computational formulae, calculate the:\r<BR>\n" );
document.write( "\n" );
document.write( "(i) estimated mean.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #803183 by </B><A HREF=/tutors/aboutme.mpl?userid=Solver92311><B>Solver92311(821)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Solver92311><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=Solver92311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=803183\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "To calculate the estimated mean: Find the midpoint of each interval.  Multiply the midpoints by the associated frequencies.  Add the products.  Divide the sum by the total number of data observations (sum of the frequency numbers).\r<BR>\n" );
document.write( "\n" );
document.write( "																<BR>\n" );
document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi}\ +\ 1\ =\ 0\"><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/display-illustration.mpl?tutor=Solver92311&illustration_name=darwinfish.jpg\">\r<BR>\n" );
document.write( "\n" );
document.write( "From <https://www.algebra.com/cgi-bin/upload-illustration.mpl> <BR>\n" );
document.write( "I > Ø<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\Large \ \\r\"> </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );