The blood groups of 200 people are distributed as follows: 50 have type A blood, 65 have B blood type, 70 have O blood type and 15 have type AB blood. If a person from this group is selected at random, what is the probability that this person has O blood type?
Construct a table of frequencies for the blood groups
Table of frequencies is as given below
Blood group Frequency
A 50
B 65
O 70
AB 15
Total frequency is 50+65+70+15=200
If a person is randomly selected from this group, the probability that he has O blood type is,
sample size is 200
Number of people with blood group O is 70
Probability that the randomly selected person has blood type O is 70/200=7/20.
Thus, the probability that this person has O blood type is 7/20.
Comments
Leave a comment