Do by hand to learn. See patterns
1 1
1 2
1 2
3 4
10 20
30 40
1 3
4 3
P(x)+P(x̄)=1
P(x|y)+P(x̄|y)=1 ...
A,B disjoint
0 x
y 0 x,y not 0
smoker - CO oximetry
49 57
24 370
drug job applicants
45 5
25 480
driving&texting
731 3054
156 4564
marijuana test
119 3
24 154
cancer
8 2
99 891
polygraph Rearranged!
42 9
15 32
INDEPENDENCE: rows and columns are multiples of each other
10 30
20 60
3blue1brown
9 1
89 901