Insert the geometric means.

-1,_,-125,_,-3125

sorry, you don't have a constant ratio

125/1 ≠ 3125/125

However, the sequence could have r=±5, if the first term were -5 instead of -1.

x^2 = (-1)(-125) = 125

x = ±5√5

since -1 is your first term, ±5√5 also becomes the r value .

y^2 = (-125)(-3125) = 390625
y = √390625 = 625

your GP
if r = +√125
the sequence is -1, -√125, - 125, -125√125, - 15625
if r = -5√5
the sequence is -1, +√125, - 125, +125√125, - 15625

something is wrong here.
I was expecting -3125 , as was stated in your problem
If a, b, c, form a geometric sequence,
then b^2 = ac, that is the square of any term must equal the product
of the terms on either side of it

To find the geometric means, you need to find the square root of each pair of consecutive numbers in the sequence.

The given sequence is: -1, _, -125, _, -3125

First pair: -1 and -125
The square root of -1 is not a real number, so we can't calculate the geometric mean in this case.

Second pair: -125 and -3125
The square root of -125 is -5.
The square root of -3125 is not a real number.

Therefore, we can only calculate the geometric mean for the second pair: -5.

So, the geometric means are: -5.

The geometric mean is a type of average that is calculated by taking the nth root of the product of a set of numbers. In order to find the missing geometric means in the sequence -1, _, -125, _, -3125, we can use the formula for geometric mean.

The first step is to identify the common ratio between the numbers. In this sequence, each term is obtained by multiplying the previous term by -5. So, the common ratio is -5.

To find the first missing term, we need to determine the square root of -1 multiplied by -5. The square root of a negative number is an imaginary number because the square of any real number is always positive. In this case, the square root of -1 is denoted by the imaginary unit "i." Therefore, the first missing term is -5i.

To find the second missing term, we need to determine the square root of -125 multiplied by -5. Using similar logic, the square root of -125 is 5i√5, and when multiplied by -5, it becomes -25i√5.

So, the sequence with the geometric means filled in is: -1, -5i, -125, -25i√5, -3125.