课程名称︰统计学一上
课程性质︰必修
课程教师︰王衍智
开课学院：管理学院
开课系所︰财务金融学系
考试日期（年月日）︰101.11.21 / 11.28 / 12.05 / 12.19
考试时限（分钟）：15/10/10/15
是否需发放奖励金：是
（如未明确表示，则不予发放）
试题 :
Statistics I Quiz 3 Date: 21 Nov 2012 Time: 9:10-9:25.
1. A joint probability chart is shown below: (30%):
Y=1 Y=2 Y=3 Y=4
X=1 0.1 0 0 0
X=2 0.2 0.05 0.15 0
X=3 0.15 0.05 0.1 0.2
a) Please write fX|Y(X=a|Y=b).
b) Please find E(X|Y)
c) Please find E(X*Y0.5|Y)
2. A census suggests 0.5% of man get liver cancer at their 40. If Mr. White in
his 40 gets screened for liver cancer and receives a positive test result.
The medical examination he did has error for 1 positive test out of 1000
healthy people and for 10 negative tests out of 1000 people with liver cancer.
What is the probability that he does have liver cancer? (30%)
3. A lottery has 20% of rate to draw a prize. Find the probability of winning
twice out of buying 8 lotteries. (20%)