Chapter 1
Defn: Statistics:
1) are commonly known as numerical facts
2) is a field of discipline or study
Here, statistics is about variation.
3 main aspects of statistics:
1) Design (Think): Planning
Ch. 16 Random Variables
Defn: A random variable is a numerical measurement of the outcome of a random
phenomenon.
A discrete random variable is a random variable that assumes separate values.
# of peo
Ch. 7 Scatterplots, Association, and Correlation
So far, weve seen univariate data. This section, however, considers bivariate data and
how two numerical variables are related. Methods of description
Ch. 14 Introducing Probability
Defn: An experiment is a process that, when performed, results in one and only one of
many observations (or outcomes).
Probability is a numerical measure of likelihood t
Ch. 18 - Sampling Distributions
Expanded defn: A parameter is: - a numerical value describing some aspect of a popn
- usually regarded as constant
- usually unknown
A statistic is: - a numerical value
Ch. 19 - Statistical Inference
Defn: Estimation is the assignment of value(s) to a population parameter based on a
value of the corresponding sample statistic.
An estimator is a rule used to calculate
Ch. 23 CI for a Population Mean
- common situation is that is unknown, so the sample data must estimate it.
Y
Y
. We now have Z
Recall Z =
= t , where t is a diff. standardized variable.
/ n
s/ n
T
Ch. 24 - Comparing Two Population Means
Assumptions:
1. The two samples are random and independent.
2. At least one of the following is also true:
i. Both samples are large (n1 30 and n2 30)
ii. If ei
Ch. 20 - Hypotheses and Test Procedures
Defn: A null hypothesis is a claim about a population parameter that is assumed to be
true until it is declared false.
An alternative hypothesis is a claim abou
Ch. 11 13 - Gathering Data
Defn: An observational study is a study where a researcher observes characteristics of
subjects in samples from populations of interest.
A retrospective study is an observat