|
|
发表于 14-12-2010 10:55 PM
|
显示全部楼层
本帖最后由 junchung2003 于 14-12-2010 11:40 PM 编辑
7. 3/5
8. k=11
9. b. Mean = 2 , Variance = 1.8 (b对了a就会对的)
10. a. F(x) = (-1/3)(x)(e^(-x/3)) - (e^(-x/3)) + 1
b. P(X>9) = 1 - F(9)
= 0.199
11. n=28
using Poisson distribution, X~Po(2)
P(X>3) = 0.1429
12.
a. 这个靠whyyie
b. Median = 6.1
Semi-interquartile range = 1/2
c. No affect on median. Affect semi-interquartile range. Because the data fall into the first quartile group but not median group.
d.i. 18.2%
ii. 6.1 , reason: no big change on the data (这个我不懂)
如果有错请告诉我 |
|