Answer:
second term: 9
4th term:81
[tex](3rd \: term)^{2} = 9 \times 81[/tex]
=729
[tex] \sqrt{729} = 27[/tex]
3rd term=27
[tex] {9}^{2} = a1x27 \\ 81 = 27a1[/tex]
a1=3 the first term
[tex]81 = 3 \times {q}^{3} [/tex]
[tex] {q}^{3} = 27[/tex]
q=3
[tex]s = 3x \frac{1 - {3}^{5} }{1 - 3} = 364.5[/tex]
