00:01
In order to find the missing terms in this geometric sequence, normally we would take our common ratio and just multiply the previous term to get to the next.
00:12
However, our terms that we know are too far spaced apart to do that, and we don't know what our common ratio is.
00:21
So instead, we're going to have to find the geometric mean.
00:28
And the geometric mean is always going to give you the number, in the middle of your two outside numbers.
00:36
So since the two outside numbers we have right now are 12 .5 and 5 .12, our geometric mean is going to give us this center term here.
00:49
So in order to calculate the geometric mean, you take the two outside numbers, 12 .5 and 5 .12, and 5 .12, and you multiply them together.
01:03
Then you take the square root of that number, and that number will give you that center term.
01:13
So 12 .5 times 5 .12 is 64, and the square root of 64 is 8, which means that this center term is 8...