Given the following 2D training points:

A(1,1) - Red, B(2,2) - Red, C(3,3) - Blue, D(4,4) - Blue, E(2,3) - Blue

Using K=3 and Euclidean distance, how would a new point P(2.5, 2.5) be classified?

Question

Given the following 2D training points: 
 
A(1,1) -> Red, B(2,2) -> Red, C(3,3) -> Blue, D(4,4) -> Blue, E(2,3) -> Blue

Using K=3 and Euclidean distance, how would a new point P(2.5, 2.5) be classified?

Answer

Red — because point A is the closest

Answer

Blue — because 2 out of 3 nearest neighbours are Blue

Answer

Red — because the two nearest red points outweigh the single blue

Answer

Cannot be determined without normalisation

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