Chapter 1
1-1:
Statistics 1: refers to numerical facts, 2: refers to numbers/refers to the field or discipline of
study. Statistics is a group of methods used to collect, analyze, present, and interpret data and
to make decisions.
descriptive statistics: The set of methods used to organize, display, and describe data./ consists of
methods for organizing, displaying, and describing data by using tables, graphs, and summary
measures.
inferential statistics/ inductive reasoning or inductive statistics: Collection of methods that help
make decisions about a population based on sample results./ consists of methods that use sample
results to help make decisions or predictions about a population.
Element/member/observation unit: A specific subject or object included in a sample or
population
variable: a characteristic under study that assumes different values for different elements. In
contrast to a variable, the value of a constant is fixed.
observation/ measurement : The value of a variable for an element.
data/ data set: Collection of observations or measurements on one or more variables.
1: quantitative Variable :can be measured numerically .
Discrete Variable: values are countable. assume only certain values with no intermediate values
Continuous Variable : can assume any numerical value over a certain interval or intervals
2: qualitative /Categorical Variable: cannot assume a numerical value, but can be classified into
two or more nonnumeric categories
Basic on time collection:
o cross-section: date collected in different element of population or sample in the same period
o time-series data: date collect for the same element in different point in time
, ? compute the values for expressions that are presented in summation notation.
1-3
o population vs. sample
Population or Target Population :consists of all elements—individuals, items, or objects.
Sample: A portion of the population selected for study. Reason: time, cost and
Impossibility of Conducting a Census
o census vs. sample survey
Census survey : A survey that includes every member of the population is called a census.
A sample survey :that includes only a portion of the population is called a sample survey.
o sampling with replacement vs. sampling without replacement
Representative Sample A sample that represents the characteristics of the population as
closely as possible is called a representative sample.
sampling with replacement, each time we select an element from the population, we put it
back in the population before we select the next element.
Sampling without replacement occurs when the selected element is not replaced in the
population.
A population is the collection of all elements whose characteristics are being studied. A
sample is a portion of the population selected for study. A representative sample is a
sample that represents the characteristics of the population as closely as possible. Sampling
with replacement refers to a sampling procedure in which the item selected at each
selection is put back in the population before the next item is drawn; sampling without
replacement is a sampling procedure in which the item selected at each selection is not
replaced in the population.
o random vs. non-random samples
A random sample is a sample drawn in such a way that each member of the population has
some chance of being selected in the sample. A random sample is usually a representative
sample
1-1:
Statistics 1: refers to numerical facts, 2: refers to numbers/refers to the field or discipline of
study. Statistics is a group of methods used to collect, analyze, present, and interpret data and
to make decisions.
descriptive statistics: The set of methods used to organize, display, and describe data./ consists of
methods for organizing, displaying, and describing data by using tables, graphs, and summary
measures.
inferential statistics/ inductive reasoning or inductive statistics: Collection of methods that help
make decisions about a population based on sample results./ consists of methods that use sample
results to help make decisions or predictions about a population.
Element/member/observation unit: A specific subject or object included in a sample or
population
variable: a characteristic under study that assumes different values for different elements. In
contrast to a variable, the value of a constant is fixed.
observation/ measurement : The value of a variable for an element.
data/ data set: Collection of observations or measurements on one or more variables.
1: quantitative Variable :can be measured numerically .
Discrete Variable: values are countable. assume only certain values with no intermediate values
Continuous Variable : can assume any numerical value over a certain interval or intervals
2: qualitative /Categorical Variable: cannot assume a numerical value, but can be classified into
two or more nonnumeric categories
Basic on time collection:
o cross-section: date collected in different element of population or sample in the same period
o time-series data: date collect for the same element in different point in time
, ? compute the values for expressions that are presented in summation notation.
1-3
o population vs. sample
Population or Target Population :consists of all elements—individuals, items, or objects.
Sample: A portion of the population selected for study. Reason: time, cost and
Impossibility of Conducting a Census
o census vs. sample survey
Census survey : A survey that includes every member of the population is called a census.
A sample survey :that includes only a portion of the population is called a sample survey.
o sampling with replacement vs. sampling without replacement
Representative Sample A sample that represents the characteristics of the population as
closely as possible is called a representative sample.
sampling with replacement, each time we select an element from the population, we put it
back in the population before we select the next element.
Sampling without replacement occurs when the selected element is not replaced in the
population.
A population is the collection of all elements whose characteristics are being studied. A
sample is a portion of the population selected for study. A representative sample is a
sample that represents the characteristics of the population as closely as possible. Sampling
with replacement refers to a sampling procedure in which the item selected at each
selection is put back in the population before the next item is drawn; sampling without
replacement is a sampling procedure in which the item selected at each selection is not
replaced in the population.
o random vs. non-random samples
A random sample is a sample drawn in such a way that each member of the population has
some chance of being selected in the sample. A random sample is usually a representative
sample
