Stat 133 Recitation
3.1 and 3.2
Samples, Surveys, and Experiments
1.
Which of the following sampling plans uses some form of random selection? (Choose
all that apply)
a. Simple random sampling.
b. Stratified random sampling.
c. Self-selected (volunteer) s
Stat 133 Recitation
Section 1.1
1. Which of the following data sets is more spread around the mean, the first or the
second?
30
Fr e que ncy
40
30
Fr e que ncy
40
20
20
10
10
0
20
40
60
80
0
100
20
40
60
80
100
2. We collected data OVER time and put it in
STAT 133
Midterm 1A Autumn 2011
SOLNS
1. It is possible for a person to have different scores on two exams but still be at the 95 th percentile in both cases.
a. True (95th percentile means 95% of the scores are below you, whatever those scores are. It do
Suggested Problems for 2.1-2.4
SCATTERPLOTSANDREGRESSION
1.
WhentwovariablesXandYdecreasetogether,wedescribethenatureoftheirassociationasa
negativelinearrelationship.
a. True
b. False
2.
8.Supposeyoucollectdataontwovariables,X,andY.Anyscatterplotthatshow
2.1-2.2
Scatterplots and Correlation
1. A professor examines the relationship between minutes studying and exam score (out
of 200 points) for students in his course using data from 320 randomly selected students.
Use the results below to answer the follow
Stat 133 Recitation
Section 4.3
1. Which of the following statements is always true? (If all are always true, select d)
a.
X+Y = X + Y
b.
XY = X * Y
c.
2X+Y = 2X + 2Y
d.
All of the above are always true.
2.
Suppose X is always -3. Then 2X = _.
a. -3
b. 9
Stat133Recitation
Section4.4:SamplingDistributionofXbar( X )
1.
TheCentralLimitTheoremstatesthat,ifarandomsampleofsize n isdrawnfroma
population,thenthesamplingdistributionofthesamplemean X :
a. isapproximatelynormalifn>30
b. isapproximatelynormalifn<30
c
Stat 133 Recitation
5.1
Section5.1:ProbabilityRules
1.
IfAandBaredisjointeventswithP(A)=0.70,thenP(B):
a. canbeanyvaluebetween0and1
b. canbeanyvaluebetween0and0.70
c. cannotbelargerthan0.30
d. cannotbedeterminedwiththeinformationgiven
2.
IfP(A)=0.65,P(B)=
Stat 133 Recitation
Section 5.2
Multiple Choice and True/False
1.
If P(A) = 0.35, P(B) = 0.45 and P(A and B) =0.25, then P(A|B) is:
a. 1.4
b. 1.8
c. 0.714
d. 0.556
2.
If two events are independent, what is the probability that they both occur?
a. 0
b. 0.5
Stat 133 Recitation
Section 5.3
Section 5.3: Binomial Distribution
1. The national proportion of adults who are concerned about nutrition is 0.35. You take a
random sample of 20 adults and count the number who are concerned about nutrition
(call this numb
Stat 133 Recitation
Section 6.1: Confidence intervals for the sample mean
Note: All confidence intervals are 95% unless otherwise indicated. This also applies
on exams.
1. Suppose you want to estimate the average number of years employees have worked at
y
Stat 133 Recitation
Probability Practice
1.
Twoormoreeventsaresaidtobeindependentwhentheoccurrenceofoneeventhasno
effectontheprobabilitythatanotherwilloccur.
a.True
b.False
2.
JimandJohngotoacoffeeshopduringtheirlunchbreakandtossacointoseewhowill
pay.Th
1. The law of total probability is used to find a conditional probability that is not
directly given in the problem.
a. TRUE
b. FALSE
2. For any two events A and B, P(A and B) = P(A)*P(B)
a. TRUE
b. FALSE
3. To use the addition rule to find P(A or B), you
Stat 133 Recitation 11/22/2011
Name(s)_
Group Number_
Normal, Binomial, and Approximation to the Binomial
FOR ALL PBMS: DRAW PICTURES SHOWING WHAT YOU HAVE AND WHAT YOU
WANT. SHOW ALL WORK!
#1-9: DETERMINE WHETHER YOU NEED PERCENTAGES OR PERCENTILES.
T
STAT 133
MIDTERM 1A
AU 2011
NAME_
RECITATION TIME (T, TH)_
COMPUTER/GROUP NUMBER_
TOTAL NUMBER OF POINTS ON THIS EXAM: 250. THERE ARE 42 PROBLEMS.
NOTE: IN FAIRNESS TO ALL STUDENTS, WE CAN NO LONGER ANSWER QUESTIONS DURING OUR
EXAMS. ANSWER THE QUESTIONS
Stat 133 Recitation
Section 1.3
Stat 133 Recitation
Section 1.3
1. Suppose Math exam scores have a normal dist with mean 70 and s = 10 and stat exam
scores have a normal dist with mean 80 and SD 5.
a. Draw a picture of the distribution of math scores. Dra
Stat 133 Recitation
Section 1.2
1.
Inahistogram,theproportionofthetotalareawhichmustbetotheleftofthemedianis:
a. exactly0.50
b. lessthan0.50ifthedistributionisskewedtotheleft
c. morethan0.50ifthedistributionisskewedtotheright
d. between0.25and0.60ifthedis
Midterm Review WI 2010
1. Data from a travel study contain many variables. Which of the following variables are
categorical (aka qualitative) and which are quantitative? Fill in the table by making a
check in the appropriate box for each variable.
VARIABL
Suggested Problems for 2.1-2.4
SCATTERPLOTSANDREGRESSION
1.
WhentwovariablesXandYdecreasetogether,wedescribethenatureoftheirassociationasa
negativelinearrelationship.
a. True
b. False
2.
8.Supposeyoucollectdataontwovariables,X,andY.Anyscatterplotthatshow
Probability
Basic Terms and Notation
Midterm 2 Review
Sections 5.1, 2.5, 5.4, 4.3
Independent events
Definition
Disjoint events
aka Mutually Exclusive
Definition
Examples
How to check
How to check
Are disjoint events independent?
How not to check
Types of
STAT 133 Midterm 2A AU 2011
MC/TF SOLUTIONS
1. If X and Y are independent, the standard deviation of X+Y equals the standard deviation of X plus the standard
deviation of Y.
a. TRUE
b. FALSE
2. If X and Y are independent, the variance of X Y equals the va
STAT 133
MIDTERM 2A
AU 2011
NAME_
RECITATION TIME (T, TH)_
COMPUTER/GROUP NUMBER_
TOTAL NUMBER OF POINTS ON THIS EXAM: 250. THERE ARE 31 PROBLEMS.
NOTE: IN FAIRNESS TO ALL STUDENTS, WE CAN NO LONGER ANSWER QUESTIONS DURING OUR
EXAMS. ANSWER THE QUESTIONS
Probability Advice from Dr. Rumsey
We know probability is a difficult subject and we are here to help. Here Ive written a
compilation of the advice Ive given students over the years who have asked me How can I
study to do well on this exam? Doing these th
Different Types of Probability Questions - Solutions
Problem 1
For two events A and B, suppose that P(A | B) = 0.5, P(B | A) = 0.25, and P(A and B) = 0.10.
a. Find P(A or B).
b. Are A and B independent events?
Solution:
What we know: P(A | B) = 0.50, P(B
Different Types of Probability Questions
Problem 1
For two events A and B, suppose that P(A | B) = 0.5, P(B | A) = 0.25, and P(A and B) = 0.10.
a. Find P(A or B).
b. Are A and B independent events?
Problem 2
A researcher is testing ESP (Extra-Sensory Perc
Stat 133 Final Exam Info (Monday evening March 12, 5:30-7:120 in INDEPENDENCE
100):
The final is comprehensive and worth 250 points. It has much more weight on material after
midterm 2. Here is a description of the plan for the final exam so you can prepa
STAT 133
FINAL A
AU 2011
NAME_
RECITATION TIME (T, TH)_
COMPUTER/GROUP NUMBER_
TOTAL NUMBER OF POINTS ON THIS EXAM: 250. THERE ARE 30 PROBLEMS.
NOTE: IN FAIRNESS TO ALL STUDENTS, WE CAN NO LONGER ANSWER QUESTIONS DURING OUR
EXAMS. ANSWER THE QUESTIONS TO
Chapters and Sections
for Midterm 1
Stat 133
Midterm 1 Review
1.1 Graphing data
What are the two types of data?
1.1 Continued
How do we graph quantitative data?
1.1: Graphing data
1.2: Summarizing data with numbers
3.1: Taking samples and doing surveys
3.