Question

Suppose that the second term of a geometric sequence is 4 and the sixth term is 16. Find the fourth term

Answer 1

• 8

Explanation:

Given GP

• a₂ = 4,
• a₆ = 16

To find

• a₄ = ?

Solution

• a₂ = ar = 4
• a₆= ar⁵ = 16

Substitute ar in the second equation

• ar⁵= 16
• 4r⁴ = 16
• r⁴ = 4
• r = √2

Then finding a₄

• a₄ = a₂*r² = 4*(√2)² = 4*2= 8