STAT 420: Homework #8
Spring 2015, Dalpiaz
Due: April 3, 3:00PM
You may use R for all problems on this homework. Please circle or highlight relevant output where
possible.
Problem 1
Chemists often use ion-sensitive electrodes (ISEs) to measure the ion con
STAT 420: Homework #5
Spring 2015, Dalpiaz
Due: March 6, 3:00PM
Problem 1
A society of bird watchers has collected data from several towns on stork sightings (x) and human
births (y) to test the widely expressed belief that storks bring babies. Assume tha
STAT 420 N1
Spring 2013
Homework #1
(due Friday, January 25, by 3:00 p.m.)
1.
Suppose that the amount of beer a person has consumed ( X ) and the persons
blood alcohol level ( Y ) in a certain bar follow a bivariate normal distribution with
X = 60 oz,
a)
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
1.
Examples for 01/15/2013
Spring 2013
A large class took two exams.
Suppose the exam scores X
( Exam 1 ) and Y ( Exam 2 )
follow a bivariate normal
distribution with
1 = 70,
1 = 10,
2 = 60,
2 = 15,
= 0.6.
a)
A students is selected at random
STAT 420
Fall 2013
Homework #1
(due Friday, September 6, by 4:00 p.m.)
1.
If the price of gasoline goes up, the prices of the other goods tend to go up too.
Suppose the price of a gallon of gas ( X ) and the price of a gallon of milk ( Y )
at Anytown foll
STAT 420
1.
Practice Problems 2
Spring 2015
Dalpiaz
Do NOT use a computer for this problem.
x
y
An Anytown State University student wishes to examine
2
567
the relationship between the monthly rent amount for an
2
728
apartment ( y ) (in $) and the number
STAT 420
Homework 1:
Spring 2014
Due February 4 by 7:00pm
Exercise 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 dist
STAT 420
Fall 2012
Homework #1
(due Friday, September 7, by 3:00 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
Homework #2
(10 points) (due Friday, February 2, by 4:00 p.m.)
Spring 2007
From the textbook:
4.5
Prove the algebraic identity
J n
j =1 i =1
(Yij Y )2 =
J j =1
n Yj Y
(
)2 +
J
n
j =1 i =1
(Yij Y j )2
J nj
j =1 i =1
(Yij Y )
=
2
=
J nj
j =1 i =1
(
STAT 420: Exam #1
Spring 2015, Sections: DU, DG
Solutions
Name:
NetID:
Be sure to show all your work; your partial credit might depend on it.
No credit will be given without supporting work.
Place your answers in the space provided.
You may use a calculat
STAT 420
Sections U3, G4
Fall 2014
A. Stepanov
Homework #11
(due Friday, December 5, by 3:00 p.m.)
No credit will be given without supporting work.
Put your name (with your last name underlined) and your NetID
on the top of the first page.
1.
In order to
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.
STAT 420
Homework 6:
Spring 2014
Due March 19 by 7:00pm
Exercise 1
Chemists often use ion-sensitive electrodes (ISEs) to measure the ion concentration of aqueous solutions. These devices measure the migration of the charge of these ions and give a
reading
STAT 420
Fall 2012
Homework #6
(due Friday, October 19, by 3:00 p.m.)
Chemists often use ion-sensitive electrodes
ppm
mV
(ISEs)to measure the ion concentration of
aqueous solutions. These devices measure the
migration of the charge of these ions and give
STAT 420: Homework #7
Spring 2015, Dalpiaz
Due: March 20, 3:00PM
You may use R for all problems on this homework. Please circle or highlight relevant output where
possible. Perform any tests at an = 0.05 signicance level.
Problem 1
The data set mammals fr
STAT 420
Fall 2012
Homework #3
(due Friday, September 21, by 3:00 p.m.)
1.
Do NOT use a computer for this problem.
An employee claims that drinking beer has no effect on the amount of time it takes for
him to perform a particular task. The following data
STAT 420
Fall 2013
Homework #5
(due Friday, October 11, by 4:00 p.m.)
No credit will be given without supporting work.
Put your name and your NetID on the top of the first page.
1.
An Anytown State University student wishes to examine
x
y
the relationship
STAT 420
Homework 7:
Spring 2014
Due April 4 by 7:00pm
Exercise 1 (revisited)
Chemists often use ion-sensitive electrodes (ISEs) to measure the ion concentration of aqueous solutions. These devices measure the migration of the charge of these ions and giv
STAT 420
Fall 2013
Homework #4
(due Friday, September 27, by 4:00 p.m.)
No credit will be given without supporting work.
Put your name and your NetID on the top of the first page.
1.
Do NOT use a computer for this problem.
x
y
An Anytown State University
STAT 420
2GR, 2UG, 3GR, 3UG
Spring 2016
A. Stepanov
Homework #3
(due Friday, February 12, by 3:00 p.m.)
Please include your name ( with your last name underlined ),
and your NetID at the top of the first page.
No credit will be given without supporting wo
STAT 420: Homework #7
Spring 2015, Dalpiaz
Due: March 20, 3:00PM
You may use R for all problems on this homework. Please circle or highlight relevant output where
possible. Perform any tests at an = 0.05 signicance level.
Problem 1
The data set mammals fr
STAT 420 U3, G4
Fall 2013
Version B
Page
1
2
Name
ANSWERS
.
Exam 1
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
The exam is closed book and closed notes.
You are allowed
STAT 420
Fall 2013
Homework #7
(due Friday, October 25, by 4:00 p.m.)
7.3
Using the ozone data, fit a model with O3 as the response and temp,
humidity and ibh as predictors. Use the Box-Cox method to determine
the best transformation of the response.
> li
STAT 420
Fall 2010
Homework #7
(due Friday, October 22, by 3:00 p.m.)
1.
The dataset prostate comes from a study on 97 men with prostate cancer
who were due to receive a radical prostatectomy. ( Andrews D. F. and Herzberg
A. M. (1985): Data. New York: Spr
STAT 420
Spring 2016
Name
Version A
Page
ANSWERS
NetID _
Earned
Exam 2
Be sure to show all your work; your
partial credit might depend on it.
1
2
No credit will be given
without supporting work.
3
Place your answers
in the space provided.
4
The exam is cl
STAT 420: Homework 10
Fall 2016, Dalpiaz
Due: Monday, November 14 by 11:59 PM CDT
Directions
Assignment
Exercise 1 (TV Is Healthy?)
Exercise 2 (Brains)
Exercise 3 (EPA Emissions Data, Redux)
Exercise 4 (Bigger Is Better?)
Directions
Students are enc
STAT 420
2GR, 2UG, 3GR, 3UG
Fall 2016
A. Stepanov
Examples for 10/04/2016 (1)
ANOVA (Analysis of Variance)
Population 1
mean 1
Population 2
mean 2
std. dev.
std. dev.
y 11 , y 21 , , y n11
Population J
mean J
std. dev.
y 12 , y 22 , , y n22
y 1J , y 2J
STAT 420
2GR, 2UG, 3GR, 3UG
3.
Fall 2016
A. Stepanov
Examples for 10/18/2016 (part 2)
A company wishes to study the effects of three different types of promotion on
sales of its cookies. The three promotions were:
Treatment 1 Sampling of product by custom