The two-way table shows the results of a recent study on What is the probability that a randomly selected person
the effectiveness of the flu vaccine.
who tested positive for the flu is vaccinated?
465
Pos.
Neg.
Total
o 2,321
O
465
1,236
Vaccinated
465
771
1,236
465
950
0
Not
Vaccinated
485
600
1,085
465
485
0
Total
950
1,371
2,321