Answer:
0.085 round to the nearest thousandth
A variable represents an unknown number
So 2.5^2= 1.5^2 +b^2
6.25= 2.25 +b^2
Subtract 2.25 on each side
4= b^2
Take the square root of each side
X=2
Hope it helps
To find n-therm of a geometric sequence, we are going to use the formula

where:

is the term we are looking for

is the first term

is the ratio

is the position of the number in the sequence
From the question we now that

,

, and

. Lets replace those values into our formula to get:



We can conclude that in our geometric sequence

; therefore, the answer is
A.