Explanation

To find the geometric mean, we need to multiply the numbers together and then take the nth root, where n is the number of values.

In this case, we have 4 numbers: 1, 2, 8, and 16.

First, multiply them together:

1 × 2 × 8 × 16 = 256

Then, take the 4th root (since there are 4 numbers):

256^(1/4) = 4

So, the geometric mean is 4.