Name
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The Normal Distribution
The 68-95-99.7 Rule
Normal models give us an idea of how extreme a value is by telling us how likely it is to nd one that far
from the mean. We can nd these numbers precisely, but until then we will u
Name:
SOCI 202, Spring 2013
Solutions to Exam 1 Review Problems
1. It is estimated that between 28 and 34 percent of registered voters nationwide feel that the Republican party can
do a better job of handling immigration issues.
2. The population is all A
Name
Chp 5 SSDS and Chp 8 Salk
The Normal Distribution
Normal Distribution
A bell-shaped and symmetrical theoretical distribution, with the mean, the median, and the mode all coinciding
at its peak and with frequencies gradually decreasing at both ends of
SOCI 202, SPRING 2012
EXAM 2; March 27, 2012;
Part I: In Class Portion 75 points
Name (1 point):
Instructions: Closed book. Calculator allowed. Double-sided exam. NO CELL PHONES. Show all work
to receive full credit! Write legibly.
Multiple Choice (3pts e
Practice Problems for Exam 2
1. Which of the following is NOT true about the normal distribution?
A) it is bell-shaped
B) it is symmetrical
C) it is an empirical distribution
D) the mean, median, and mode coincide at its peak
2. Considering the properties
1. A measure of how unusual or rare an obtained statistics is referred to as:
A) alpha
B) beta
C) z-score
D) p-value
2. Calculate the degrees of freedom for a one sample t-test with 2,822 U.S. adults between
the ages of 15 and 64 in the sample.
3. Suppose
Name:
SOCI 202, Springl 2013
Exam 1 Review Problems
The problems below are intended as practice problems to help prepare for the in-class portion of Exam 1. The
problems are intended to help serve as a guide to studying material from Chapters 1-4 and part
Social Statistics - SOCI 202
Katelyns Pivot Table and Segmented Bar Chart Hints
Pivot Table Creation
1. Under the Insert tab, select Pivot Table, the icon on the far left.
2. The Create Pivot Table dialog box will appear. Click into the eld marked Table/R
Situation
I am asked something about
averages or means. As in: is
the mean number of times per
day I walk to campus different
from 3?
I am asked something about
proportions or percentages. As
in: Test whether a recent
survey provides evidence to
suggest t
Social Statistics - SOCI 202
Katelyns Histogram Hints
1. Installing the Data Analysis ToolPak:
(a) If you are running Excel on Mac, stop, and use computers in MSU Student Labs instead. Roberts
Hall 109 & 110, Reid 306, and the Library all have Excel on Wi
Soci 202
Chp 1 SSDS and Salk
What is Empirical Research?
Research based on information that can be veried by using our direct experience.
Empirical: Are women paid less than men for the same types of work?
Not Empirical: Is racial equality good for soci
Soci 202
Chp 2 SSDS and Chp 4 Salk
Part 1
Frequency Distribution
A table reporting the number of observations falling into each category of the variable.
Example: Death Penalty Statutes
In 1993, 36 states and Washington, D.C. had statutes permitting capi
Soci 202
Chp 2 SSDS and Chp 4 Salk
Part 2
Graphical Representations
It is important to choose the appropriate graphs to make statistical information coherent.
The Pie Chart
a graph showing the dierences in frequencies or percentages among categories of
Soci 202
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Measures of Central Tendency
Numbers that describe what is average or typical of the distribution. You can think of this value as where the
middle of a distribution lies.
The Mode
The category or score with the largest
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Chp 4 SSDS and Chp 3 Salk
Measures of Spread
1.1 Sampling
When necessary, we use statistics to estimate parameter values. In order to do so, however, the sample
must be representative of the population. That is, the statistics we calculate based on a
Chp 6 SSDS
The Central Limit Theorem
February 11, 2013
Exploring the Sampling Distribution of the Sample Mean
Imagine there are only 5 people in the universe. Our goal is to nd the mean height of the population of 5
people in the universe.
Population
Pers
Name
SOCI 202: Chp 6
The Central Limit Theorem Continued
February 13, 2013
Central Limit Theorem
For a relatively large sample size n, the variable X is approximately normal, regardless of the distribution
under consideration. The approximation becomes be
Name
SOCI 202
Chapter 6 : Condence Intervals
February 25, 2013
Construction of a Condence Interval
From Gallup.com: A record-high 50% of Americans now say the use of marijuana should be made
legal, up from 46% last year. Forty-six percent say marijuana us
SOCI 202
Chapter 6 Continued
February 27, 2013
Class Exercise Do Not Hand In
1. Consider our class to be our population for todays exercise. Let the random variable X = the blood
pulse rate of a randomly chosen student in our class. Assume the standard de
SOCI 202
Chp 7: Testing Hypotheses
March 22, 2013
An Introduction to Hypothesis Testing
Quality Assurance A company that produces snack foods uses a machine to package 454 g bags of pretzels.
We assume that the net weights are normally distributed and tha
SOCI 202
Chp 7 Part 2
A Review of Condence Interval for Means
When the assumptions/conditions are met, the condence interval for the mean is given by:
x z .
n
Here, in our example today, is approximated with the sample standard deviation.
Condence Interva
Basic Properties of the t-distribution
SOCI 202
Chp 7 : Learning to use the t-table
total area under the t-curve is 1
The Students t-distribution
the curve extends indenitely in both directions
the curve is symmetric about 0
There will be a dierent t-