Probability and Statistics in Engineering and Science
MATH 390

Winter 2013
O. #r
QUIZ 5
(1O
minutes, 34 pointsi
vah.res of y ONLY iwith no plots made at a11i.
al Revise the functi.on make.fitt) so that it +rill return the predicted
b) Writ* code tc pr:cduce the scatterplot of fhe predicted values" whert there is nc collineari
Probability and Statistics in Engineering and Science
MATH 390

Winter 2013
Math 309 C  Spring 2010
Final Exam
une 7,2410
Name:
Student Number:
a
t
2
15
ar
J
25
4
5
6
t5
20
Total
r
10
1.00
15
READ ALL DIRECTIONS CAREFLJLLX
r
Complete all (nonbonus) questions.
.
You may use a scientific, nongraphing calculator during this exam
Probability and Statistics in Engineering and Science
MATH 390

Winter 2013
Math 309 C  Autumn 201,1,
MidTerm Exam
November 2,2011
Name:
Student Number:
1
2
3
4
5
Total
r
READ
AtL DIRECTIONS
20
25
25
20
10
100
LO
7I
1b
Zo
4
8A
CAREFULLY.
o Complete all questions.
o You may use a scientific, nongraphing calculator during this
8.23 revised.
Consider the following sample observations: 2781, 2900, 3013, 2856, and 2888.
Suppose we want to do a twosided test of the pop mean, i.e.,
H0: mu = 3000
H1: mu != 3000
a) Compute the pvalue, and state the conclusion "In English" (i.e., is
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
Suppose we are developing a new composite material for building airplain
wings. We take a sample of size 100 of the material and test its breaking
strength under a set of standard conditions. The sample mean and sample
standard deviation of the breaking s
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
a) Read the data file bias_0_data.txt into R (it's on the course website), perform regression to predict y from x, make the
scatterplot of the predictions versus the observed y values, and overlay a diagonal line (yintercept=0, slope=1) on it. BUT,
becau
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
MOE = c
(29.8,33.2,33.7,35.3,35.5,36.1,36.2,36.3,37.5,37.7,38.7,38.8,39.6,41.0,42.8,42.8,43.5,45
.6,46.0,46.9,48.0,49.3,51.7,62.6,69.8,79.5,80.0)
Strength = c
(5.9,7.2,7.3,6.3,8.1,6.8,7.0,7.6,6.8,6.5,7.0,6.3,7.9,9.0,8.2,8.7,7.8,9.7,7.4,7.7,9.7,7.8
,7.7,11
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
In R, write code to
a) take a sample of size 100 from a normal distribution with parameters mu = 1, sigma = 2, and compute the sample mean and
sample standard deviation for that sample.
n = 100
mu = 1
sigma = 2
x = rnorm(n,mu,sigma)
mean(x)
sd(x)
b) mak
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
8.23 revised.
Consider the following sample observations: 2781, 2900, 3013, 2856, and 2888.
Suppose we want to do a twosided test of the pop mean, i.e.,
H0: mu = 3000
H1: mu != 3000
a) Compute the pvalue, and state the conclusion "In English" (i.e., is
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
MOE = c
(29.8,33.2,33.7,35.3,35.5,36.1,36.2,36.3,37.5,37.7,38.7,38.8,39.6,41.0,42.8,42.8,43.5,45
.6,46.0,46.9,48.0,49.3,51.7,62.6,69.8,79.5,80.0)
Strength = c
(5.9,7.2,7.3,6.3,8.1,6.8,7.0,7.6,6.8,6.5,7.0,6.3,7.9,9.0,8.2,8.7,7.8,9.7,7.4,7.7,9.7,7.8
,7.7,11
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
2 Distributions
2.1 Binomial and Poisson Distribution
# The format is dbinochu, n, pi), where ct: = number of heads out of n tosses of a
# coin, and pi = prob of head. For example,
dbinomCO, 100, 0.005) # returns the value of the distribution (10me itsel
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
A sample of 2000 aluminum screws used in the assembly of electronic
components was examined, and it was found that 44 of these screws
stripped out during the assembly process. Does it appear that at most
2.5% of these screws suffer from this defect? Expla
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
11.18 revised
Mist (airborne droplets or aerosols) is generated when metalremoving fluids are used in
machining operations to cool and lubricate the tool and workpiece. Mist generation is a concern
to OSHA, which has recently lowered substantially the w
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
Suppose we are developing a new composite material for building airplain wings.
We take a sample of size 100 of the material and test its breaking strength
under a set of standard conditions. The sample mean and sample standard
deviation of the breaking s
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
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Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
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Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
QUIZ 1
Write code to a) readin the data in the following URL, and call it
DAT:
http:/www.stat.washington.edu/marzban/390/spring17/gamma_dat.txt b)
assign the second column of DAT to a variable called x. c) sort x
d) select the first and the last elements
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
QUIZ 3
In the prelab you learned how to simulate data from the binomial
distribution with a fixed pi value (0.5) but different n values
ranging from 1 to 100 (in integer steps). A figure was made showing
the sample mean and the sample variance versus the
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
QUIZ 2
In this quiz we will play with distributions, histograms, and
boxplots. Intro: You can use forloops to make many of the grahs in
the prelab. For example, the following will make the one on page 8 of
the prelab:
x = 0:20 par(mfrow=c(3,4) for( n in
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
Statistical Methods in Engineering and Science, STAT/MATH 390
This is a fluid syllabus, so check frequently for changes in colors
Instructor: Caren Marzban (The best way to reach me is email)
Class Times and Room: MWThF, 2:303:20, THO 101
Quiz/Lab Sessio
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
A sample of 2000 aluminum screws used in the assembly of electronic components was
examined, and it was found that 44 of these screws stripped out during the assembly
process. Does it appear that at most 2.5% of these screws suffer from this defect?
Expla
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
8.23 revised.
Consider the following sample observations: 2781, 2900, 3013, 2856, and 2888.
Suppose we want to do a twosided test of the pop mean, i.e.,
H0: mu = 3000
H1: mu != 3000
a) Compute the pvalue, and state the conclusion "In English" (i.e., is
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
For each of the data sets a) hw_3_dat1.txt and b) hw_3_dat2.txt, find the "best" leastsquare fit, and report Rsquared and the standard deviation of the errors. Do not use
some ad hoc criterion to determine what is the "best" fit. Instead, use your knowle
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
For the data shown here:
x= 45, 58, 71, 71, 85, 98, 108
y = 3.20, 3.40, 3.47, 3.55, 3.60, 3.70, 3.80
a) Compute the eq. of the OLS fit.
b) Compute the total variation, SST.
c) Decompose it into explained and unexplained.
d) Compute R2 and interpret it (in
Probability and Statistics in Engineering and Science
MATH 390

Winter 2014
Suppose we are developing a new composite material for building airplain
wings. We take a sample of size 100 of the material and test its breaking
strength under a set of standard conditions. The sample mean and sample
standard deviation of the breaking s