Answer:
324 and 144
Step-by-step explanation:
We require
a₁, a₂, a₃, a₄
where a₂ and a₃ are the required geometric means
The n th term of a geometric sequence is
= a₁
where a₁ is the first term and r the common ratio
Here a₁ = 729 and a₄ = 64, thus
729(r³) = 64 ( divide both sides by 729 )
r³ = ( take the cube root of both sides )
r = = , then
a₂ = 729 × = 81 × 4 = 324
a₃ = 324 × = 36 × 4 = 144
Thus
729, 324, 144, 64