TAMU STAT 211 Exam 1
Define: categorical variable - Answer variable that takes values in one of several
categories
ex: gender, race, major
Define: quantitative variable - Answer variable that takes numerical values where
arithmetic makes sense
ex: age, SAT score, time until arrival
Define: observational study - Answer Passive data collection. Nothing is done to
influence the variables on the units in the sample.
tends to be more cost effective
Define: experiment - Answer Treatment is applied to some units. Variables on units are
measured with the intention of determining if the treatment affects the variables.
Whats the difference between a histogram and a bar graph? - Answer Histogram bars
touch and their width is related to the value range, used for quantitative data
Bar graph bars do not bars touch and their width is not related to the value range, used
for categorical data
Define: Unit - Answer Single entity who's quantity is measured
Define: Population - Answer The entire set of units
Define: Sample - Answer A set of selected units and their associated measurements
Define: census - Answer Sample that attempts to include entire population
Define: Parameter - Answer Fixed (and usually unknown) number that describes the
population
Define: Statistic - Answer Number from the sample that estimates a population
parameter
Define: Randomized experiment - Answer Subjects are randomly assigned to the
assigned and control groups
Define: Double-blind experiment - Answer Neither the subjects nor those collecting the
data know who is the control/experimental group
Define: categorical variable - Answer variable that takes values in one of several
categories
ex: gender, race, major
Define: quantitative variable - Answer variable that takes numerical values where
arithmetic makes sense
ex: age, SAT score, time until arrival
Define: observational study - Answer Passive data collection. Nothing is done to
influence the variables on the units in the sample.
tends to be more cost effective
Define: experiment - Answer Treatment is applied to some units. Variables on units are
measured with the intention of determining if the treatment affects the variables.
Whats the difference between a histogram and a bar graph? - Answer Histogram bars
touch and their width is related to the value range, used for quantitative data
Bar graph bars do not bars touch and their width is not related to the value range, used
for categorical data
Define: Unit - Answer Single entity who's quantity is measured
Define: Population - Answer The entire set of units
Define: Sample - Answer A set of selected units and their associated measurements
Define: census - Answer Sample that attempts to include entire population
Define: Parameter - Answer Fixed (and usually unknown) number that describes the
population
Define: Statistic - Answer Number from the sample that estimates a population
parameter
Define: Randomized experiment - Answer Subjects are randomly assigned to the
assigned and control groups
Define: Double-blind experiment - Answer Neither the subjects nor those collecting the
data know who is the control/experimental group
