# Question about weighted midpoint formula

The answers from these two replies seem to contradict each other. The first numerator is bidSizebidPrice + askSizeaskPrice but the second is bidSizeaskPrice + askSizebidPrice.

Price functions based on order book events

Control for bid/ask bounce in high-frequency trade data?

Does anyone know what I'm missing here?

Edit: I think the 2nd link above is correct formula but I'm likely misreading first link. This because this paper seems to agree with 2nd link: http://home.uchicago.edu/~shim/Papers/HFT-FrequentBatchAuctions.pdf