atop in American English. (əˈtɑp ) adverb. 1. on the top; at the top. preposition. 2. on the top of. Webster’s New World College Dictionary, 4th Edition.
SEE definition: When you see something, you notice it using your eyes. | Meaning, pronunciation, translations and examples
A Sample: divide by N-1 when calculating Variance. All other calculations stay the same, including how we calculated the mean. Example: if our 5 dogs are just a sample of a bigger population of dogs, we divide by 4 instead of 5 like this: Sample Variance = 108,520 / 4 = 27,130. Sample Standard Deviation = √27,130 = 165 (to the nearest mm)
To expand on it a bit, "at the top" could be just in the area of the top, such as the top of a mountain, or building. "On the top" would be the highest surface of that mountain, or building, so "on" would be higher than "at" in that respect. In the same way, you will sometimes hear an athlete say he/she is "at the top of my game" to indicate
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