This preview shows pages 1–3. Sign up to view the full content.
Section 1.1
How Can You Investigate Using Data?
May 11, 2009
1
1 Statistics: The Art and Science of
Learning from Data
Disclaimer: Unless otherwise stated, all statements in quotes are taken directly from our
textbook Agresti/Franklin, 2007.
1.1 How Can You Investigate Using Data?
“The information we gather with
experiments
and with
surveys
is collectively called
data
.”
“
Statistics
is the art and science of designing studies and analyzing the data that
those studies produce. Its ultimate goal is translating data into knowledge and
understanding of the world around us. In short,
statistics
is the art and science
of learning from data.”
Where is statistics used in the real world?
Example:
2000 U.S. Senatorial election in New York, with 6,253,883 voters (out of
19 million New Yorkers, including children).
Based on an exit poll from sampling 2232 voters (0.036% of voters):
Democrat Hillary Rodham Clinton (56%), Republican Rick Lazio (44%)
Is it reasonable to conclude that Clinton won, based on that exit poll?
*
Yes.
{
Standard error is about 1%, so margin of error is about 1
.
96
×
1%
≈
2%. Clinton
won 55% to 43% with the remaining votes going to third party candidates.
} {
This
is sample surveys. Other examples include estimating unemployment rate, approval
of President’s foreign policy in Mexico.
}
*
Yes.
{
Standard error is about 1%, so margin of error is about 1
.
96
×
1%
≈
2%. Clinton
won 55% to 43% with the remaining votes going to third party candidates.
} {
This
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document Section 1.1
How Can You Investigate Using Data?
May 11, 2009
2
is sample surveys. Other examples include estimating unemployment rate, approval
of President’s foreign policy in Mexico.
}
Example:
Test marketing. Will revenues increase if a company starts marketing a
new product?
*
Around 1985 CocaCola changed its formula and called the new product
New Coke
.
*
Around 1985 CocaCola changed its formula and called the new product
New Coke
.
Example:
Suppose there is an 80% chance of rain.
*
What does this mean? This exempliFes
climatology
.
*
What does this mean? This exempliFes
climatology
.
Example:
Global warming
* {
We study global warming via data, see Agresti/±ranklin, chapter 2.
}
* {
We study global warming via data, see Agresti/±ranklin, chapter 2.
}
*
An example regarding average annual temperature in Central Park from 1901 to 1997
is on p. 43.
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 10/22/2009 for the course MATH 220 taught by Professor Ruffin during the Fall '07 term at James Madison University.
 Fall '07
 Ruffin
 Math, Statistics, The Federalist Papers

Click to edit the document details