## anonymous 4 years ago Determine the 5th term of an infinite geometric series if S(infinite)=18 and r=2/3

$Sum = \frac{a}{1-r}$ $18=\frac{a}{1-\frac{2}{3}}$ $54=a$ $a _{n}=a _{1}r ^{n-1}$ $a _{5}=54(\frac{2}{3})^{4}=54(\frac{16}{81})=\frac{32}{3}$