Download Graphical Methods

BA 275
Winter 2007
Introduction
Statistics is the science of data. It involves collecting, classifying, summarizing,
organizing, analyzing, and interpreting numerical information.
Fundamental Elements of Statistics
A population is a set of units (usually people, objects, transactions, or events) that we are
interested in studying. It is the totality of items or things under consideration.
A sample is subset of the units of a population. It is the portion of the population that is selected
for analysis.
A parameter is a numerical descriptive measure of a population. It is a summary measure that is
computed to describe a characteristic of an entire population. Because it is based on the
elements in the population, its value is almost unknown.
A statistic is a numerical descriptive measure of a sample. It is a summary measure calculated
from the observations in the sample.
Types of Data
Quantitative/Numerical Data
 Values are real numbers.
 Arithmetic calculations are valid.
 Examples include SAT scores, Age, Income, etc.
Qualitative/Categorical Data
 Values represent the names of possible categories, and do not have usual numerical
meaning.
 Usual arithmetic calculations are not valid.
 Examples: Use the number 0 to represent a male student, and 1 to represent a female
student.
Hsieh, P-H
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BA 275
Winter 2007
Introduction
Doing Statistics Circle
POPULATION
parameters: , 2, , p, etc.
Drawing conclusions from data:
Estimation
Hypothesis Testing
Regression Analysis
Contingency Tables
Selecting a random sample:
X1, X2, …, Xn
Organizing data:
Qualitative
Quantitative
Sample of size n
x1, x2, …, xn
statistics:x , s2, s,p̂ , etc.
Describing uncertainty:
Random variables,
Probability,
Distributions
Discrete: binomial distribution
Continuous: normal distribution,
Sampling distribution of the sample mean
Hsieh, P-H
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