Chp 1.
1.18 A researcher studies the average distance that 130 people living in U.S. urban areas walk each week.
a. What is the size of the sample?
b. Identify the population.
c. Is this average a descriptive statistic or an inferential statistic if it is
1
Frances Ramos
PS307
Instructor Stewart
Assignment 1
Chapter 1
1.18 A researcher studies the average distance that 130 people living in the U.S. urban areas
walk each week.
a. What is the size of the sample?
Sample size: 130 people
b. Identify the popula
Assignment #3
1. The McBurger restaurant chain claims that the mean waiting time of consumers is 3 minutes with a population
standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the
Warren road McBurger tha
Statisitcs
Name Jessica Gonzalez
Homework #1
1.
9
8
7
6
5
4
3
2
1
0
The following scores were made by Professor Dougs A. Meany's statistics
students on a test:
68
57
61
52
60
90
49
88
85
69
47
66
74
65
72
41
55
63
59
68
95
a)
Arrange the above grades in a
Ch 7
Between any two points there is an infinite amount of points. So there is no width
between two points; any point estimation is wrong but and interval is accurate.
For elections a candidate might say 38% or 35% to 41% because it is impossible to be
ri
11/09/2010
Proportions
N=500
X=135
99%
Z=2.575
p Z (p)
.272.575 (
p ( 1 p )
n1
)
P=135/500=.27
p
p ( 1 p )
n1
N n
N 1
for a large population the correction factor is
always 1 so no need to use if large
.27 ( 1.27 )
5001
=
.27 ( .73 )
499
=.02*2.575=.0515
Ch 6.
Simple Random Sampling-whole population is represented
Stratified Random Sampling- divide into sublists then sample from sublist
Cluster Sampling- Selecting groups of cases (in vicinity) custer within cluster (zip codes or area, then
blocks or sides
11/11/2010
Hypothesis testing is just testing a claim
5 steps:
1. Ho: =
2. HA: <, >,
3. Rejection Criteria: Choose CI and (ie. Z=2.575 for 95% CI)
x o
s
4. Test statistic: Z=
n
5. Decision (compared to rejection criteria)
reject
reject
Accept
Type 1 erro
11/4/2010 Notes
Make sure to go online and find the next homework as well as some handouts to help with what we are
doing.
%CI
(alpha)
Beyond Z
SD
95%
.05
.025
1.96
96%
.04
.03
1.885
Core Assessment Project: Regression Analysis
Find topic of interest to y
Descriptive statistics
1. distribution of a single variable (univariate or one variable)
2. relationship between 2 or more variables (bivariate: two variables) or (multivariate: more than 2)
Discrete variable- cant be divided into protions (2.8) (ie. Peop
Question#4:Offeryouclassmatesagoodwaytodistinguishbetweenindependentand
dependentvariablesmakesuretheywillunderstandyourexplanation.
Here is a great example that I found on the web.
Example:
Can blueberries slow down aging? A study indicates that antioxid
Chapter 5: 5.28, 5.42
5.28 Convert the following proportions to percentages:
a. 0.0173 = 1.73%
b. 0.8 = 80%
0.0173 x 100
.08 x 100
c. 0.3719 = 37.19%
0.3719 x 100
5.42 Random selection or random assignment: For each of the following hypothetical scenario
Chapter 1: 1.18,1.26, 1.28
1.18
A researcher studies the average distance that 130 people living in U.S. urban areas walk each
week.
a. What is the size of the sample?
The sample size is 130.
b. Identify the population.
The population is that of people wh
An Introduction to Statistics and
Research Design
Chapter 1
Two Branches of Statistics
Descriptive statistics
Organize, summarize, and communicate
numerical information
Inferential statistics
Use samples to draw conclusions about a
population
Samples and
Chapter 3: 3.18, 3.30, 3.41
3.18 Alumni giving rates for a number of universities, calculated as the number of alumni who
donated and the number who did not donate in a given year, represent which kind of variable
nominal, ordinal, or scale? What would b
7.22 Using the z table in Appendix B, calculate the following percentages for a z score of 2 0.08:
a. Above this z score
P (z > 0.08) = 0.5319
b. Below this z score
P (z < 0.08) = 0.4681
c. At least as extreme as this z score
P (z 0.08) + P (z 0.08) = 2 x
Assignment #3
1. The McBurger restaurant chain claims that the mean waiting time of consumers is 3 minutes with a population
standard deviation of 1 minute. The quality-assurance department found in a sample of 50 customers at the
Warren road McBurger tha