Ch. 16 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 an estimate.
An estimate is a specific value of an estim
Ch. 6 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 are introduced here and
formalized in Ch. 24.
Ch. 15 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 describing some aspect of a sample
- regarded as random
Ch. 14 Random Variables
Defn: A random variable is a numerical measurement of the outcome of a random
A discrete random variable is a random variable that assumes separate values.
# of people who think stats is dry
The probability distributio
Ch. 12 From Randomness to 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 that a specific outcome occurs.
3 Conceptual Appr
Ch. 17 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 about a population parameter that will be true
if the null hy
Ch. 9 11 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 observational study in which subjects are selected and
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 how to obtain data to answer questions.
Statistics 252 Formula Sheet Paul Cartledge
Numerical Summaries: For a r.s. (y1, , yn) of size n
Sample Mean: Y y
n i 1
( yi y )
sY i 1
d [tn 1, /2] [ s d / n ]
Two Means Independent