Question

A geometric series has second term

Answer 1

Answer:  243/5 = 48.6

Step-by-step explanation:

  a₁,  375,  a₃,   a₄,  81 , a₆

First, let's find the ratio (r). There are three multiple from 375 to 81.

$375r^3=81\\\\r^3=\dfrac{81}{375}\\\\\\r^3=\dfrac{27}{125}\qquad \leftarrow simplied\\\\\\\sqrt[3]{r^3} =\sqrt[3]{\dfrac{27}{125}}\\ \\\\r=\dfrac{3}{5}$

Next, let's find a₆ which is one multiple from 81.

$a_6=81\bigg(\dfrac{3}{5}\bigg)^1\\\\\\.\quad =\large\boxed{\dfrac{243}{5}}$