(a),
The common ratio between the terms is
[tex]\frac{972}{324}=\frac{324}{108}=3[/tex](b).
The common ratio found in (a) tells us that every next number is found by dividing the previous number by 3; therefore, the equation for a_n the nth term will be
[tex]a_n=\frac{972}{3^n}[/tex](c).
The sixth term will be at n = 6. Putting n = 6 into the equation in (b) gets us
[tex]a_6=\frac{972}{3^6}=\frac{4}{3}[/tex]