Statistics 431 Practical Final Exam
Cuto values possibly of use (notation consistent with the textbook):
z0.05 = 1.645, z0.025 = 1.960,
t0.05,35 = 1.689, t0.025,35 = 2.030,
1
t0.05,32 = 1.694, t0.025,32 = 2.037.
Problem 1. The production manager of an oce
Stat 431 Midterm Exam Solution, Spring 2012
March 20, 2012
Problem 1.
(1) Denote the average reading of the monitor by .
We test H0 : = 118 vs H1 : = 118.
The test statistic is T =
.403.
X 0
,
S/ n
and the observed test statistic is t =
x118
6.2/ 25
=
118
Statistics 431 Midterm Exam
July 17, 2014
Instructor: Anru Zhang
Notes up to one side of letter sized paper is allowed. An ordinary calculator is also allowed.
Books, other notes, and computers are not allowed. Turn o all cell phones.
The time allowed
Statistics 431 PRACTICE Midterm
Section 001/002
Notes up to two sides of letter sized paper are allowed. An ordinary calculator is also allowed.
Books, other notes, and computers are not allowed. Turn o all cell phones.
The time allowed is two hours.
Sample Mean
Sample
Covariance
Sample SD
Quality of Point Estimator
One Sided CIs:
P(L ) 1
P( U) 1 -
Sample
Correlation
-1 r 1
P-value: the probability under H0 of obtaining a test statistic as
least as extreme as current observed value. Always 0 p-value
Solutions to Statistics 431 Midterm Exam
March 2013
Instructor: Zongming Ma
Problem 1.
(1) [8 points]
Answer: We would like to test whether the two means are the same. So the null and the
alternative hypotheses are
H0 : A = B
vs. H1 : A = B
Note that it i
Summer 2014
Stat 431
Lecture 9 (July 16)
Sampling distribution
Sample mean
iid
Suppose X1 , X2 , , Xn F with E(Xi ) = , Var(Xi ) = 2 . An intuitive estimator for is
the sample mean
n
1
X=
Xi .
n
i=1
Based on the mean and variance information of Xi , we h
Summer 2014
Stat 431
Lecture 4 (July 9th)
Anru Zhang
Review of Probability (continued)
Variance, covariance, correlation and standard deviation of random variables
The variance of a random variable is a non-negative number which describes how widely
spea
Statistics 431 Midterm Exam
Section 001/002
March 14, 2012
Instructor: Zongming Ma
Notes up to four sides of letter sized paper are allowed. An ordinary calculator is also allowed.
Books, other notes, and computers are not allowed. Turn o all cell phone
Summer 2014
Stat 431
Homework 1 (50 points total)
Due: 07/11(Friday) 11:00am before class
1. (Inclusion-exclusion principle)
Suppose A1 , A2 , A3 are three events, the inclusion-exclusion principle for three events is
given as follows,
P (A1 A2 A3 ) = P (
Solution
STAT 431
Midterm Spring 431
1.a Most battery lives concentrate in a certain range and its unlikely to
expect very long battery lives. So the distribution of battery lives is rightscrewed and a log-transformation helps to obtain normally distribut
Final Exam Solution Spring 2012
Stat 431, Section 001/002
Total Points = 100
S SE/(n 2), so the MLE
1. (1) (5 points) Note that in the simple regression the RMSE is
of 2 is SSE/n = 56.542 56/58 = 3086.538
(2) (5 points) (b). The F test for testing H0 : N
Statistics 431 Final Exam
Section 001/002
May 10, 2011
Instructor: Zongming Ma
Notes up to four sides of letter sized paper are allowed. An ordinary calculator is also allowed.
Books, other notes, and computers are not allowed. Turn o all cell phones.
Statistics 431 Practical Final Exam
Cuto values possibly of use (notation consistent with the textbook):
z0.05 = 1.645, z0.025 = 1.960,
t0.05,35 = 1.689, t0.025,35 = 2.030,
1
t0.05,32 = 1.694, t0.025,32 = 2.037.
Problem 1. The production manager of an oce
Summer 2014
Stat 431
Quiz 1 (50 points total)
07/11(Friday) 11:00am - 11:30am
1. (25 points) There are imbalanced numbers of women and men in quite a few numbers of
Asian countries, such as China and India. Moreover, these countries happen to have the
his
Statistics 431 Practice Midterm Exam
Cuto values possibly of use (notation consistent with the textbook):
z0.05 = 1.64,
z0.025 = 1.96.
1
Problem 1.
1. Problem 1 Homework 2:
(a) Which one will be probably be larger mean or median?
(b) Will the sample skewn
Statistics 431 Midterm Exam
Section 001/002
February 28, 2013
Instructor: Zongming Ma
Notes up to four sides of letter sized paper are allowed. An ordinary calculator is also allowed.
Books, other notes, and computers are not allowed. Turn o all cell ph
Statistics 431 Midterm Exam
Section 001/002
March 19, 2014
Instructor: Nathan Stein
Notes up to four sides of letter sized paper are allowed. An ordinary calculator is also allowed.
Books, other notes, and computers are not allowed. Turn o all cell phon
Spring 2013
Stat 431
Homework 1 (110 points)
Due on Friday, February 1 at 5 pm.
Please turn in a hardcopy either in class or use the STAT 431 box in Statistics Department (400
JMHH). For problems involving computation with R, please only report results. D
STAT 431 Midterm Review Spring 2013
TA: Tengyuan Liang, WHP 17
1. Statistical Inference and Hypothesis Testing
1.1 Point Estimation and Confidence Interval
1.2 Hypothesis Testing
Sampling Distribution:
Point Estimation:
Sample Mean and Sample Variance T
Fall 2014
STAT 431
Homework 3
Due on Friday, October 17 at 5 pm.
Please turn in a hardcopy either in class or use the STAT 431 box in Statistics Department (400
JMHH). For problems involving computation with R, please report your results rst followed by
t
Summer 2014
Stat 431
Homework 1 (50 points total)
Due: 07/11(Friday) 11:00am before class
1. (Inclusion-exclusion principle)
Suppose A1 , A2 , A3 are three events, the inclusion-exclusion principle for three events is
given as follows,
P (A1 A2 A3 ) = P (
Summer 2014
Stat 431
Homework 4 solution
Due: 08/04(Monday) 11:00am before class
For the problems involving computation in R, please report results and attach the R source
code.
1. (R practice problem) The time between eruptions of Old Faithful geyser in
Spring 2013
Stat 431
Homework 2
Due on Friday, February 15 at 5 pm.
Please turn in a hardcopy either in class or use the STAT 431 box in Statistics Department (400
JMHH). For problems involving computation with R, please only report results. Do not turn i
Lectures on Hypothesis Testing
Stat 431, Summer 2012
Hyunseung Kang
July 10 - 12, 2012
Last Updated: July 12, 2012 11:59PM
1
Introduction
So far, with the sample we collected, we were able to do the following
1. Summarize the sample with numerical summari
Summer 2014
Stat 431
Homework 4
Due: 08/04(Monday) 11:00am before class
For the problems involving computation in R, please report results and attach the R source
code.
1. (R practice problem) The time between eruptions of Old Faithful geyser in Yellowsto