document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=978921>Question 978921</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The second term in a geometric sequence is 50. The fourth term in the same sequence is 112.5. What is the common ratio in this sequence? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #600270 by </B><A HREF=/tutors/aboutme.mpl?userid=htmentor><B>htmentor(1343)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=htmentor><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=htmentor><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=600270\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The nth term of a geometric sequence can be written a_n = a + (n-1)d, where a is the 1st term and d is the common difference<BR>\n" );
document.write( "So we can write the 1st 4 terms as <BR>\n" );
document.write( "a_1 = a<BR>\n" );
document.write( "a_2 = a + d<BR>\n" );
document.write( "a_3 = a + 2d<BR>\n" );
document.write( "a_4 = a + 3d<BR>\n" );
document.write( "Given: a_2 = 50, a_4 = 112.5<BR>\n" );
document.write( "subtract a_2 from a_4 to determine d:<BR>\n" );
document.write( "a + 3d - (a + d) = 112.5 - 50<BR>\n" );
document.write( "2d = 62.5<BR>\n" );
document.write( "d = 31.25 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );