Key Definitions
Descriptive Statistics
Population - collection of things under study
Sample - a portion of the population
Parameter - a number computed to describe
a feature of the population
Statistic - a number computed to describe a
feature of the samp

Important Terms
Basic Probability
Experiment any process that generates
outcomes
Sample space the collection of all possible
outcomes of an experiment
Experiment Sample Space
Ex.1
Throw a die once
Ex.2
Draw one card from a bridge deck
Experiment Sample Sp

Bernoulli Experiment
The Binomial Distribution
An experiment for which there are only 2 possible
outcomes : success (S) or failure (F), e.g.
Toss a coin once : head / tail
Quality inspection : acceptable / unacceptable
Market research survey : buy / n

Why Study Sampling Distributions
Sampling Distribution of the Mean
Otis Lift Company is responsible for repair and maintenance
of its lifts. A typical lift has a capacity for roughly 20
persons and carries a maximum weight of 3000 lb.
What is the chance t

Random Variable
Random Variables
and Their Properties
Outcomes of an experiment expressed
numerically
e.g. Throw a die twice; X = number of 4
(0, 1, 2)
e.g. Toss a coin once; Y = the number of heads
(0, 1)
T
Probability Distribution
Experiment : Toss a fa

Scatter Plot
Linear relationships
Linear Correlation Analysis
Nonlinear relationships
Y
Y
X
X
Y
Y
X
X
Linear Correlation Coefficient
i 1
n
X
i 1
i X
2
n
Y Y
i 1
i
2
X
i
X Yi Y
n 1
i 1
n
i 1
X
i
X
n 1
2
n
i 1
Y
Y Y
i
n 1
2
0<r<1
X
Sign reflects the

Exploring Data Patterns
Components of a Time Series
A time series consists of data that are recorded
over regular or irregular intervals of time.
e.g. Daily closing price of a stock
Strength of earthquakes
Seasonal pattern - change that repeats itself yea

The Normal Distribution as an Approximation to
a Binomial Distribution
Normal Distribution
Equation of a Normal Curve
The Normal Distribution
Bell-shaped
Symmetrical
Area under curve = 1
X ~ N()
y
y
Mean
x
1
2
e
1 x
2
2
e 2.7183 (base of natural logar

Point Estimates
Interval Estimation of the Mean
Estimate Population
Parameters
Mean
Variance
Proportion
Point Estimation
Population
Population
mean, , is
unknown
Random
Sample
Mean
X = 50
I estimate
to be 50, but
how about its
accuracy ?
2
with Sample
S