The contingency table below provides a joint frequency distribution for a random sample of patients at a hospital classified by blood type and sex.
If a person is selected at random from the sample,find the probability that the person has blood type A and is female.
A)0.746
B)0.590
C)0.244
D)0.990
E)0.422

Question

The contingency table below provides a joint frequency distribution for a random sample of patients at a hospital classified by blood type and sex. 
If a person is selected at random from the sample,find the probability that the person has blood type A and is female.
A)0.746 
B)0.590 
C)0.244 
D)0.990 
E)0.422

Quizplus · Accepted Answer

The probability of a person having blood type A and being female is given by the entry in the cell where the row for blood type A and the column for female intersect, divided by the total sample size. So, the probability is: 
P(blood type A and female) = 33/135 = 0.244. 
Therefore, the best choice is C.

The Contingency Table Below Provides a Joint Frequency Distribution for a Random