STAT 420
Spring 2012
Homework #1
(due Friday, January 27, by 4:00 p.m.)
1.
a)
At Anytown College, the heights of female students are normally distributed with
mean 66 inches and standard deviation 1.5 inches. The heights of male students are
also normally
STAT 420 N1
Spring 2013
Homework #8
(due Friday, March 29, by 3:00 p.m.)
1.
Do NOT use a computer for this problem. Show all work.
( That is, do NOT use a computer at first, but then use it anyway to double-check your work. )
The data below represent the
STAT 420 N1
Spring 2013
Name
Version A
Page
ANSWERS
Earned
Exam 1
2
Be sure to show all your work; your
partial credit might depend on it.
3
4
No credit will be given
without supporting work.
5
Place your answers
in the space provided.
The exam is closed
Face Value
Annual Coupon Rate
Years to Maturity
Paymment Frequency
Value of Bond
$100.00
$100.00
$100.00
0.75%
1.375%
1.625%
2
5
10
2
2
2
$100.00
$99.61
$98.94
1/1/2010
1/1/2010
1/1/2010
12/31/2011 12/31/2014 12/31/2019
0.748%
1.456%
1.741%
Yields to Matu
STAT 420 Homework 6
1. Prostate Data (with R)
The dataset prostate comes from a study on 97 men with prostate cancer who were
due to receive a radical prostatectomy. The data frame has 97 rows and 9 columns:
lcavol
log(cancer volume)
lweight
log(prostate
STAT 420 N1
Spring 2013
Name
Exam 1
ANSWERS
.
( part 2 )
No credit will be given without supporting work.
1. (4) Suppose a complete second-order model
Y = 0 + 1 x1 + 2 x2 + 3 x3 + 4 x4 + 5 x5 + 6 x6 +
was fit to n = 27 data points.
> sum( lm( y ~ 1 )$res
STAT 420 N1
Spring 2013
Name
Version B
Page
1
2
ANSWERS
.
Exam 2
Points
Be sure to show all your work; your
partial credit might depend on it.
No credit will be given
without supporting work.
3
4
5
6
Place your answers
in the space provided.
The exam is c
STAT 420 N1
Spring 2013
Name
Version A
Page
1
2
ANSWERS
.
Exam 2
Points
Be sure to show all your work; your
partial credit might depend on it.
No credit will be given
without supporting work.
3
4
5
6
Place your answers
in the space provided.
The exam is c
STAT 420 N1
Spring 2013
Name
Version B
Page
ANSWERS
Earned
Exam 1
1
Be sure to show all your work; your
partial credit might depend on it.
2
3
No credit will be given
without supporting work.
4
Place your answers
in the space provided.
The exam is closed
STAT 420 N1
Spring 2013
Name
Exam 1
ANSWERS
.
( part 2 )
No credit will be given without supporting work.
1. (4) Suppose a complete second-order model
Y = 0 + 1 x1 + 2 x2 + 3 x3 + 4 x4 + 5 x5 + 6 x6 +
was fit to n = 27 data points.
> sum( lm( y ~ 1 )$res
STAT 420 Homework 5
1. Dating (without R)
For this exercise you are not to use R or any other software to solve the exercises. A calculator is
allowed.
A students wonders if people of similar heights tend to date each other. She measures herself,
her room
STAT 420 Homework 4
1. Restaurant Wait Times (without R)
For this exercise you are not to use R or any other software to solve the exercises. A calculator is
allowed.
A local fast food restaurant tracks certain data with regard to customer orders in order
STAT 420: Methods of Applied Statistics
Conditional MVN in R
Ruoqing Zhu, Ph.D. <rqzhu@illinois.edu>
Course website: https:/sites.google.com/site/teazrq/teaching/STAT420
University of Illinois at Urbana-Champaign
January 26, 2017
1/6
Conditional multivari
STAT 420, Homework 2
January 26, 2017
Due date: Feb 2 (Thursday), 11:59 pm
Requirements: This homework consists of two problems and worth 10 points. You should submit
your report to Compass2g (in PDF or MS word format). Your report must contain the origin
STAT 420
Spring 2015
Dalpiaz
Multiple Regression
The (normal) multiple linear regression model:
Y i = 0 + 1 x i 1 + 2 x i 2 + + p1 x i p1 + e i ,
where
i = 1, 2, , n,
e is are independent Normal ( 0 , 2 ) ( i.i.d. Normal ( 0 , 2 ) ).
0 , 1 , 2 , , p1 and
STAT 420
Examples for February 23
Spring 2015
Dalpiaz
correlation coefficient:
x x y y
2
2
x x y y
n x y x y
n x 2 x 2 n y 2 y 2
y y
r 1 x x
n 1 s x s y
r
r
r is always between 1 and + 1.
1.
The value of
2.
The magnitude of r indicates the streng
STAT 420, Homework 3
February 2, 2017
Due date: Feb 9 (Thursday), 11:59 pm
Requirements: This homework consists of two problems and worth 10 points. You should submit
your report to Compass2g (in PDF or MS word format). Your report must contain the origin
STAT 420
Spring 2015
Dalpiaz
Examples for February 4
The (normal) simple linear regression model:
Y i = 0 + 1 x i + i ,
where
is
are independent Normal ( 0 , 2 ) ( iid Normal ( 0 , 2 ) ).
0 , 1 , and 2 are unknown model parameters.
xi 2
yi y xi x yi xi
STAT 420
1.
Spring 2015
Dalpiaz
Examples for April 6, Part 3
Six samples of each of four types of cereal grain grown in a certain region were
analyzed to determine thiamin content, resulting in the following data (g/g):
Wheat
Barley
Maize
Oats
5.2
6.5
5.8
STAT 420 Homework 5
1. Dating (without R)
a.
r=
( x x )( y y )
(x x )
2
( y y )
2
=
27
24
40
= 0.87142.
b. Method 1 begins by calculating the t-test statistic.
t=
r n2
1 r
2
=
0.87142
62
1 0.87142
2
3.553.
There are n 2 = 4 degrees of freedom. According
STAT 420 Homework 3
1. Time Use (without R)
For this exercise you are not to use R or any other software to solve the exercises. A calculator is
allowed.
You are given a random sample of seven participants who participated in a large behavioral
study. Amo
STAT 420 N1
Spring 2013
Homework #12
(due Thursday, May 2, by 4:30 p.m.)
1.
Consider the AR ( 2 ) process
Yt = + 1 (Yt 1 ) + 2 (Yt 2 ) + et .
Based on a series of length N = 80, we observe , y 78 = 148, y 79 = 146, y 80 = 143,
y = 150.
a)
Suppose r 1 = 0.
STAT 420
Spring 2013
Homework #11
(due Friday, April 26, by 3:00 p.m.)
1.
Consider the AR ( 2 ) processes
&
&
&
Y t 0.9 Y t 1 + 0.2 Y t 2 = e t
where cfw_ e t is zero-mean white noise ( i.i.d. N ( 0,
a)
2
&
e ) ), Y t = Y t .
Determine whether this mode
STAT 420
Fall 2012
Homework #6
(due Monday, March 11, by 4:30 p.m.)
1.
The data in the table below came from a recent time study of a sample of 15
employees performing a particular task on an automobile assembly line.
Time to Assemble,
y (minutes)
10
20
1
STAT 420
Spring 2012
Homework #11
(due Monday, April 30, by 4:30 p.m.)
1.
Most college professors prefer to have their students participate actively in class.
Ideally, students will ask their professors questions and answer their professors
questions, mak
STAT 420
Spring 2012
Homework #10
(due Friday, April 13, by 4:00 p.m.)
No credit will be given without supporting work.
1.
Do NOT use a computer for this problem.
( But then go ahead and check your work anyway. )
An instructor wishing to cut down on cheat
STAT 420
Homework #9
Spring 2012
(due Monday, April 9, by 4:30 p.m.)
1.
skin.csv contains the average annual mortality due to malignant melanoma for
white males during 19501959 per 10 mil, for each state and the District of Columbia
( Alaska and Hawaii [
STAT 420
Spring 2012
Homework #7
(due Friday, March 16, by 4:00 p.m.)
2.2
The dataset uswages is drawn as a sample from the Current Population
Survey in 1988. Fit a model with weekly wages as the response and years of
education and experience as predictor
STAT 420
Spring 2012
Homework #8
(due Monday, April 2, by 4:30 p.m.)
1.
Do NOT use a computer for this problem.
The data below describe a random sample of 10 students who recently graduated from
Anytown State University, all majoring in Actuarial Science.