Question 851136
  <pre><font size = 3 color = "indigo"><b>
Hi,
{{{a[n] = a[1]r^(n-1) }}}
{{{a[4] = a[1]r^3 = 16/27}}} , {{{a[1] = 16/27r^3}}}
{{{a[7] = (16/27r^3)r^6 = 128/729}}}  {{{r^3 = (128/729)(27/16)}}}   r = 2/3
 {{{a[1] = 16/((27)(8/27)) = 2 }}}
{{{a[5] = 2(2/3)^4 = 32/81}}}