STAT 420 N1
Spring 2013
Homework #7
(due Monday, March 25, by 4:30 p.m.)
1.
For the prostate data, fit a model with lpsa as the response and the other
variables as predictors.
a)
Implement the Backward Elimination variable selection method to determine th
Stat 410 Probabilty and Statistics II
Lecture 2
Stat 410 Probabilty and Statistics II
Find F(x), E(X), Var(X) and moment generating function M(t) for Examples 1-4.
Example 1:
x
p( x )
1
2
3
4
x p( x )
0.2
0.4
0.3
0.1
Example 2:
2
fX( x ) = 3x
0 x 1
o.w.
0
Stat 410 Probabilty and Statistics II
Lecture 2
cumulative distribution function
c.d.f.
F( x ) = P( X x)
discrete
continuous
x
f y d y
p y
y x
Example 1:
x
p( x )
F( x )
1
2
3
4
0.2
0.4
0.3
0.1
0.2
0.6
0.9
1.0
F( x ) =
0
0.2
0.6
0.9
1
x 1
1 x 2
2 x3
3