MGSC 291 - Exam 1 Questions and Answers Latest Update 2025-2026
statistics (& two types) - Answers science of collecting, organizing, presenting, analyzing and
interpreting data to assist in decision making; descriptive & inferential
descriptive statistics - Answers methods for organizing, summarizing, and presenting data in an
informative way (graphical/tables; summary stats)
inferential statistics - Answers methods used to determine something about a population on the
basis of a sample (more conceptual)
population - Answers the entire set of objects or individuals of interest
ex: ALL state employees, EVERY facebook user in the US etc)
sample - Answers a portion or part of the population of interest
census - Answers like sample but not random, everyone is studied
cross-sectional data - Answers data recording one or more characteristic of people or items
sampled from a population AT A SINGLE POINT IN TIME
time series data - Answers data recording one or more characteristics of a person or item OVER
SEVERAL TIME PERIODS
qualitative (& two types) - Answers categorical variable, or an "attribute"
ex: hair color, bond ratings, gender, race etc
2 types: nominal, ordinal
nominal level data - Answers qualitative variables that can only be categorized and counted;
lowest level of measurement
ex: legal state of residence, brand of cereal
ordinal level data - Answers qualitative variables that can be placed into categories and then
ordered (according to which is "best" or "larger" or "more preferred"
ex: year in college (freshmen..) rating bonds (AAA...), class of air travel
quantitative (& two types) - Answers variables whose value can be counted or measured
ex: number of students, amount of gas in car, temperature
2 types: discrete, continuous
discrete variables - Answers quantitative variables that can assume only certain values and
there are usually gaps between the values; aka "counts" or count data
, ex: number of courses you're registered for etc
continuous variables - Answers quantitative variables that can assume any value within a given
interval; measured
ex: temp in room, speed of car down Greene St., annual rate of growth of GDP
quantitative data is measured on either a(n) _____ or _____ measurement scale - Answers
interval; ratio
interval-level data - Answers included all properties of ordinal data, but in addition, the difference
between successive categories is consistent
ex: temp, IQ, SAT score, shoe size
ratio-level data - Answers highest level of measurement; includes all properties of interval data
but in addition, the 0 is meaningful and therefore ratios can be formed
ex: number of gallons of gas in car, your height, your weight etc
frequency distribution - Answers table of date showing the number (or frequency) of items in
each of several non-overlapping classes; used for nominal or ordinal level data
relative frequencies - Answers reflect the proportion of the total number of observations that fall
into each category
frequency bar charts - Answers graphs of frequency distributions for qualitative data
relative frequency car charts - Answers created by plotting relative frequencies against
corresponding categories or classes
K Rule - Answers 2^k > n
Approximate class width = - Answers (Largest data value - Smallest data value) / Number of
classes
frequency histogram - Answers just the quantitative version of a frequency bar chart
relative frequency distribution - Answers divide each frequency by the total number of
observations in the data set; graph is called 'relative frequency histogram'
cumulative frequency distributions - Answers frequency + frequency before...
bimodal distribution means - Answers double-peaked; two high points
ogive - Answers connect points whose coordinates are the endpoints of the interval and the
corresponding cumulative frequency (or cum. % freq.)
statistics (& two types) - Answers science of collecting, organizing, presenting, analyzing and
interpreting data to assist in decision making; descriptive & inferential
descriptive statistics - Answers methods for organizing, summarizing, and presenting data in an
informative way (graphical/tables; summary stats)
inferential statistics - Answers methods used to determine something about a population on the
basis of a sample (more conceptual)
population - Answers the entire set of objects or individuals of interest
ex: ALL state employees, EVERY facebook user in the US etc)
sample - Answers a portion or part of the population of interest
census - Answers like sample but not random, everyone is studied
cross-sectional data - Answers data recording one or more characteristic of people or items
sampled from a population AT A SINGLE POINT IN TIME
time series data - Answers data recording one or more characteristics of a person or item OVER
SEVERAL TIME PERIODS
qualitative (& two types) - Answers categorical variable, or an "attribute"
ex: hair color, bond ratings, gender, race etc
2 types: nominal, ordinal
nominal level data - Answers qualitative variables that can only be categorized and counted;
lowest level of measurement
ex: legal state of residence, brand of cereal
ordinal level data - Answers qualitative variables that can be placed into categories and then
ordered (according to which is "best" or "larger" or "more preferred"
ex: year in college (freshmen..) rating bonds (AAA...), class of air travel
quantitative (& two types) - Answers variables whose value can be counted or measured
ex: number of students, amount of gas in car, temperature
2 types: discrete, continuous
discrete variables - Answers quantitative variables that can assume only certain values and
there are usually gaps between the values; aka "counts" or count data
, ex: number of courses you're registered for etc
continuous variables - Answers quantitative variables that can assume any value within a given
interval; measured
ex: temp in room, speed of car down Greene St., annual rate of growth of GDP
quantitative data is measured on either a(n) _____ or _____ measurement scale - Answers
interval; ratio
interval-level data - Answers included all properties of ordinal data, but in addition, the difference
between successive categories is consistent
ex: temp, IQ, SAT score, shoe size
ratio-level data - Answers highest level of measurement; includes all properties of interval data
but in addition, the 0 is meaningful and therefore ratios can be formed
ex: number of gallons of gas in car, your height, your weight etc
frequency distribution - Answers table of date showing the number (or frequency) of items in
each of several non-overlapping classes; used for nominal or ordinal level data
relative frequencies - Answers reflect the proportion of the total number of observations that fall
into each category
frequency bar charts - Answers graphs of frequency distributions for qualitative data
relative frequency car charts - Answers created by plotting relative frequencies against
corresponding categories or classes
K Rule - Answers 2^k > n
Approximate class width = - Answers (Largest data value - Smallest data value) / Number of
classes
frequency histogram - Answers just the quantitative version of a frequency bar chart
relative frequency distribution - Answers divide each frequency by the total number of
observations in the data set; graph is called 'relative frequency histogram'
cumulative frequency distributions - Answers frequency + frequency before...
bimodal distribution means - Answers double-peaked; two high points
ogive - Answers connect points whose coordinates are the endpoints of the interval and the
corresponding cumulative frequency (or cum. % freq.)
