There are 10 balls in a box, six black balls and four white balls. One man decides to
draw three balls at random. Let X denotes the number of black balls drawn. Compute
the standard deviation of X . (10%)
The probability of a husband, age 70, will die in the next year is 0.1, and the probability
that the wife, age 60, will die in the next year is 0.05. The probability that the husband
will die given that the wife dies is 0.4. What is the probability that at least one of them
will die in the next year? What is the probability that the wife will die given that the
husband has died? (20%)
可觀看題目詳解,並提供模擬測驗!(免費會員無法觀看研究所試題解答)