Question

The 4th term of an exponential sequence is 108 and the common ratio is 3. Calculate the value of the eighth term of the sequence.

Answer 1

8748

Explanation:

The formula for the nth term in a geometric sequence is ar^n-1.

We can find the first term, as a(3)^4-1 = 108 which also means that 27a = 108.

a = 4.

We find the 8th term using this:

(4)(3)^8-1 = (4)(3)^7 = 8748.