STT 231 EXAM 1 | QUESTIONS AND ANSWERS | 2026 UPDATE | 100%
CORRECT - MICHIGAN STATE UNIVERSITY.
Data is made up of ______ - (answer)Observational units
Variable - (answer)Any characteristic (or value) recorded for each case
Categorical variable - (answer)Identify a case as a measure of a group, placing each case into exactly one
of two or more groups, called levels.
Example: Year (first year, second year, third year...)
Nominal variable - (answer)Groups with no logical arrangement
Example: (eye color, major, gender)
Ordinal Variable - (answer)Groups with logical arrangement
Example: (first year, second year, third year)
Numerical variable - (answer)Measure a numerical quantity for each use.
Example: Credits (0,1,2,3)
Discrete variable - (answer)Limited values in a variables domain. No in between numbers
Example: (Number of students in a class, number of siblings...)
Continuous variable - (answer)Any value in a variables domain.
Example: (98.64, 12.347 seconds)
Why are average and proportion not variables when considering yourself to be the observational unit. -
(answer)They don't describe the characteristic of a single student. Instead, they summarize the
combined characteristics of all students simultaneously. These are actually statistics.
If you changed the observational unit to be "classes at MSU" then they would be variables.
CORRECT - MICHIGAN STATE UNIVERSITY.
Data is made up of ______ - (answer)Observational units
Variable - (answer)Any characteristic (or value) recorded for each case
Categorical variable - (answer)Identify a case as a measure of a group, placing each case into exactly one
of two or more groups, called levels.
Example: Year (first year, second year, third year...)
Nominal variable - (answer)Groups with no logical arrangement
Example: (eye color, major, gender)
Ordinal Variable - (answer)Groups with logical arrangement
Example: (first year, second year, third year)
Numerical variable - (answer)Measure a numerical quantity for each use.
Example: Credits (0,1,2,3)
Discrete variable - (answer)Limited values in a variables domain. No in between numbers
Example: (Number of students in a class, number of siblings...)
Continuous variable - (answer)Any value in a variables domain.
Example: (98.64, 12.347 seconds)
Why are average and proportion not variables when considering yourself to be the observational unit. -
(answer)They don't describe the characteristic of a single student. Instead, they summarize the
combined characteristics of all students simultaneously. These are actually statistics.
If you changed the observational unit to be "classes at MSU" then they would be variables.
