Question

What is the value of the fourth term in a geometric sequence for which a1= 30 and r= 1/2

Answer 1

`\huge\boxed{\sf a_4 = 3375}`

Explanation:

Given data:

a₁ = 20

r = 1/2

n = 4 (we have to find the fourth term)

Formula to use:

`a_n=a_1r^(n-1)` (Geometric sequence)

Solution:

Put the given data in the above formula.

So,

a₄ = (30)(1/2)⁴⁻¹

a₄ = (15)³

a₄ = 3375

`\rule[225]{225}{2}`