Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Name: Nick Achtmann
Student Number: 1167359
SOC/STAT/CSSS 221: Statistical Concepts and Methods for the Social Sciences
*Homework Assignment 6*
Please use this form to record your answers and include any work that you would like to show the
grader (you ca
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
102416
Stat 220
Homework 4
1a) Variable 1: the 8 possible colleges/universities in Washington state. The possible values are
schools like UW Seattle or Bothell, or Western or Eastern Washington.
1b) Variable 2: the 9 possible races of students
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
111416
Stat 220
Homework 7
1a) 4 children: (b x h / 2). Base is 125 90 = 35. Height is 1/35 because area is always 1.
2 children: Base is 112 90 = 22. 22/2 = 11. The other part
4 children:
Its based on a triangle shape, so you have to take the
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
101716
Stat 220
Homework 3
1a) The values are:
a1 = 10 pilots (total drug users)
a2 = 9 pilots (drug users who fail the test)
a3 = 990 pilots (clean pilots total)
a4 = 99 pilots (clean pilots who fail test)
I calculated these values by taking 1
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Describing Distributions
withhapter 2
Numbers
C
What we learned last time
Any study begins with a research question.
Depending on the question of interest, a
researcher collects data through a survey,
experiment, census or otherwise. The first
stage of da
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapters 10, 12
Probability
Outline
Probability space
Probability rules
Disjoint (mutually exclusive) events
Conditional probability
Independent events
Idea of Probability
Chance behavior is unpredictable in the short run
but has a regular and predictable
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Test Pos
P = 0.89
1/270(0.89) =
0.0033
Test Neg
1/270(0.11)=
0.00041
Downs Syndrome
Actually present
P = 1/270
P = 0.11
Test Pos
P = 0.25
Downs Syndrome
not present
269/270(0.25)
= 0.249
P = 269/270
Test Neg
BPS  5th Ed.
P = 0.75
Chapter 12
269/270(0.75)
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
STAT/SOC/CSSS 221
Picturing Distributions with Graphs
Chapter 1
BPS  5th Ed.
1
Chapter 1
What is this course about
The course will discuss, in a nonmathematical way,
the most important concepts and techniques of
statistics from the point of view of appl
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
112116
Stat 220
Homework 8
1A) The box is 1 and 0. The total of the box is 50,000 (household) tickets. Each ticket will have
a value that represents a person age 16 or ever, totaling to 400 draws in the box.
1B) EV = 400 x 2.38 = 952 interviews
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
10216
Ranjini Grove
Homework 1
1. (a) The fraction of admitted female applicants is 20/70.
(b) The two percent we should compare in order is 17/50 which is 34% for males and 8/20
which is 40% for females, so men admitted is not disproportionate
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
112816
Stat 220
Homework 9
1a) There are 50,000 (households) tickets in the box. Each ticket will have a value that represents
the average number of TV sets owned by each household. The statistician is calculating an
average of 400 draws withou
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Name: Nick Achtmann
Student Number: 1167359
SOC/STAT/CSSS 221: Statistical Concepts and Methods for the Social Sciences
*Homework Assignment 2*
Please use this form to record your answers and include any work that you would like to show the
grader (you ca
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Name: Nick Achtmann
Student Number: 1167359
SOC/STAT/CSSS 221: Statistical Concepts and Methods for the Social Sciences
*Homework Assignment 3*
Please use this form to record your answers and include any work that you would like to show the
grader (you ca
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Name: Nick Achtmann
Student Number: 1167359
SOC/STAT/CSSS 221: Statistical Concepts and Methods for the Social Sciences
*Homework Assignment 5*
Please use this form to record your answers and include any work that you would like to show the
grader (you ca
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Name: _
Student Number: _
SOC/STAT/CSSS 221: Statistical Concepts and Methods for the Social Sciences
*Homework Assignment 1*
Please use this form to record your answers and include any work that you would like to show the
grader (you can paste in photos
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Name: Nick Achtmann
Student Number:1167359
SOC/STAT/CSSS 221: Statistical Concepts and Methods for the Social Sciences
*Homework Assignment 4*
Please use this form to record your answers and include any work that you would like to show the
grader (you can
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
101016
Stat 220
Homework 2
1. a) We should NOT choose an SRS of 4,000 from 7,000 students who want basketball tickets,
because it should be first come first served for the number of students who wants to purchase
basketball ticket.
b) We should
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
11716
Stat 220
Homework 6
1a) The subject has a 35/50 (7/10) chance of being assigned to Treatment A, since the SRS of 35
is being taken out of the 50 subjects total, which is reduced down to 7/10.
1b) The second subject has a 1/2 change of bei
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Vyvy Bui
10216
Ranjini Grove
Homework 1
1. (a) The fraction of admitted female applicants is 20/70.
(b) The two percent we should compare in order is 17/50 which is 34% for males and 8/20
which is 40% for females, so men admitted is not disproportionate
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapter 24
OneWay Analysis of Variance:
Comparing Several Means
Outline
Problem description.
F test.
Analysis of Variance  ANOVA.
Conditions for ANOVA.
Problem description
Often, the studies are aimed to compare more
than two population in order to chec
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapter 23
Inference for Regression
Outline
Conditions for inference.
Estimating regression parameters.
Testing linear relationship and correlation.
Inference for regression slope.
Inference about prediction.
Linear regression
We are interested in describ
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapter 22
Two Categorical Variables:
The Chisquare Test
Outline
Association between two categorical variables.
Hypothesis of independence: expected counts.
Chisquare distribution.
Chisquare test.
Goodness of t.
Contingency tables
We are interested in
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapter 6
TwoWay Tables
Outline
Contingency tables.
Marginal distributions.
Conditional distributions.
Simpsons paradox.
Contingency tables
We are interested in describing relationships
between two or more categorical variables.
Contingency tables summar
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapter 5
Linear Regression
Linear Regression
In regression, we have two correlated variables. If we have
knowledge of the value of one variable, we can use this
knowledge to make better predictions about the value of the
other variable.
Ordinary Least Sq
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapter 4
Scatterplots and Correlation
Explanatory and Response Variables
Interested in studying the relationship
between two variables by measuring both
variables on the same individuals.
a response variable measures an outcome of a
study
an explanato
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
The Normal Distributions
Chapter 3
1
How to explore a distribution
Graphical summary (a plot, a graph, a histogram)
Overall pattern (shape, center, spread); outliers
Numerical summary to describe center and
spread.
Another way: Density Curve
Histogram
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Review
Inference for Regression
Outline
Conditions for inference.
Estimating regression parameters.
Testing linear relationship and correlation.
Inference for regression slope.
Research question
I am interested in describing a relationship
between two qua
Statistical Concepts and Methods for the Social Sciences
STATS 221

Fall 2012
Chapters 6, 22
Twoway tables, Goodness of t,
The Chisquare Test
Outline
Association between two categorical variables.
Hypothesis of independence: expected counts.
Chisquare distribution.
Chisquare test.
Goodness of t.
Independence in twoway tables
N