Probability and conditional probability · 第 2 题

Probability and conditional probability · 原库模块 1 · Q2 原库参考解析

Human blood can be classified into four common blood types—A, B, AB, and O. It is also characterized by the presence (+) or absence (-) of the rhesus factor. The table above shows the distribution of blood type and rhesus factor for a group of people. If one of these people who is rhesus negative  (-) is chosen at random, the probability that the person has blood type B is \( \frac{1}{9} \) . What is the value of x ?