Edition by Vernon Richardson, Verified Chapters 1 - 9,
Complete Newest Version
What is a population? - ANSWER: Includes all of the entities that are of interest in a
study (people, households, machines)
What is a sample? - ANSWER: a subset of the population, often randomly chosen and
hopefully representative of the population as a whole.
What is a data set? - ANSWER: usually a rectangular array of data, with variables in
columns and observations in rows
What is a variable (or field or attribute)? - ANSWER: A characteristic of elements of a
data set, such as height, gender, or salary - Columns
What is an observation (or case or record)? - ANSWER: a list of all variable values for
a single element of a data set - row
What is continuous data? - ANSWER: Continuous data are not restricted to defined
separate values (always numeric... examples include salary, time, weight, height
When is a variable numerical? - ANSWER: if meaningful arithmetic can be performed
on it.
What are the two types of numeric variables? - ANSWER: discrete and continuous
What us discrete numerical variables? - ANSWER: It is discrete if it results from a
count, such as the # of children.
These numbers do not go out into infinity
What are non-numerical variables called? - ANSWER: categorical
How many types of categorical variables are there? - ANSWER: two
Ordinal
Nominal
What is an ordinal categorical variables ? - ANSWER: if there is a natural ordering of
its possible values
EX: Credit ratings: AAA, AA, BBB
, What are nominal categorical variables? - ANSWER: If there is no natural ordering
EX: U.S. States
What are the three types of data sets? - ANSWER: Cross-sectional
Times series
Panel data
What is a cross-sectional data set? - ANSWER: datasets that contain MULTIPLE
ELEMENTS of a POPULATION at a SINGLE POINT IN TIME.
EX: the assets of each firms in the S&P 500 in the year 2000
What is a time series data set? - ANSWER: datasets are collected over time for a
single element of the population.
EX: the assets of a single firm from the years 2015-2020
What is a panel data - data set? - ANSWER: A cross-sectional and times series
combined
What is the symbol for sample mean? - ANSWER: x̄
What is the symbol for population mean? - ANSWER: μ
What is percentile? - ANSWER: for any percentile p, the pth percentile is the value
such that a percentage p pf all values is less than it
EX: if you are in the 95th percentile, 95% percent of people were less than you
What is a quartile? - ANSWER: dividing the data into four parts, each with
approximately a quarter of all observations
What are the quartile rankings? - ANSWER: Top quartile (1st) = top 25%
Bottom quartile (4th) = bottom 25%
When looking for the top quartile in excel, remember..... - ANSWER: You are looking
for >3 quartiles
AKA greater than the three bottom quartiles
What is an issue with applying mathematical operations when advance filtering in
place? - ANSWER: It will be conducted on all observations even the ones that have
been filtered out