Confusion at Three Quarters - Decision Thresholds, Exactly

Count TP, FP, FN, and TN at three quarters.

highlighted = computed this step

Count positives at three quarters

At threshold 3/4, A is TP and there are no FP rows.

TP=1,\quad FP=0

C is FN. B and D are TN, so FN=1 and TN=2.

FN=1,\quad TN=2

The confusion grid is TP=1, FP=0, FN=1, TN=2.

(TP,FP,FN,TN)=(1,0,1,2)