Question

800, 560, 392, ...
What is the 9th term in the sequence?

Answer 1

`T_9 = 46.118408`

Explanation:

Given

800, 560, 392, ...

Required

Determine the 8th term

The above sequence shows a geometric sequence and the nth term is calculated by:

`T_n = a * r^{n-1`

r is calculated by:

`r = (T_2)/(T_1)`

`r = (560)/(800)`

`r = 0.7`

`a = 800` --- First term

`n = 9`

So:

`T_n = a * r^(n-1)`

`T_9 = 800 * 0.7^{9-1`

`T_9 = 800 * 0.7^8`

`T_9 = 46.118408`