It could mean a couple of things depending on how it is used in the sentence.
One is that it means to be amazed or astonished, shock or have a strong emotion.
1. to make stupid, groggy, or insensible
2. to astonish or astound someone
The mean distance is the same as the mean of a set of numbers,but this time, instead of them just being numbers, they're lengths. You just simply add up all the numbers and divide the total length,...