Question

If a1= 7 and r=3, find a4

Answer 1

a4 = 189

Explanation:

Geometric sequence:

In a geometric sequence, the quotient r between consecutive terms is always the same.

The nth term of the sequence is given by:

`a_n = a_1*r^(n-1)`

In which
`a_1` is the first term.

In this question:

`a_1 = 7, r = 3`

The fourth term is:

`a_4 = 7*3^3 = 189`

So

a4 = 189