STATS MIDTERM WEEKS 1-4 EXAM
QUESTIONS WITH THE ONLY CORRECT
ANSWERS
puts individuals into groups (color, name, year, etc.)
includes nominal and ordinal data - answer ✔✔-Categorical data
identify a category (qualitative, attribute, categorical, or classification data and can be coded numerically
like 1 = Apple, 2 = Lenovo) - mathematical operations are performed only with counts or frequencies of
categories (you wouldn't average) - answer ✔✔-Nominal data
data codes can be ranked like 1 = Frequently, 2 = Sometimes, 3 = Rarely - distance between codes is not
meaningful (likert scale) - answer ✔✔-Ordinal data
used in survey research and allow the taker to answer a question with five scaled options like Strongly
Agree, Somewhat Agree, Neutral, etc. - answer ✔✔-Likert Scales
assigns numbers
includes discrete vs continuous and time series vs cross-sectional - answer ✔✔-Numerical data
Discrete data: countable, integer value, observed, counted on hand
Continuous data: fraction or decimal, measured by an instrument, turns into discrete by rounding -
answer ✔✔-Discrete and Continuous data
, Time Series data: each observation in the sample represents a different equally spaced point in time (we
are interested in trends and patterns)
Focuses on the same variable over a period of time
Cross-Sectional data: each observation represents a different individual unit at the same point in time
(VISA balances) and we are interested in variation or relations between them
Focuses on several variables at the same point in time - answer ✔✔-Time Series and Cross-Sectional
data
Population of N Items
Parameters: μ = population mean, π = population proportion
Sample of n Items
Statistics: x = sample mean, p = sample proportion - answer ✔✔-Population vs Sample
Simple Random Sample: use random numbers to select items from a list
Systematic Sample: select every nth item from a list or sequence
Stratified Sample: select randomly within defined strata (age, gender)
Cluster Sample: select random geographical regions that represent the population - answer ✔✔-
Random Sampling Methods
Judgment Sample: use expert knowledge to choose "typical" items
Convenience Sample: use a sample that happens to be available
Focus Groups: in-depth dialog with a representative panel of individuals - answer ✔✔-Non-Random
Sampling Methods
Nonresponse Bias: respondents differ from nonrespondents
Selection Bias: self-selected respondents are atypical
Response Error: respondents give false information
Coverage Error: incorrect specification of frame or population
QUESTIONS WITH THE ONLY CORRECT
ANSWERS
puts individuals into groups (color, name, year, etc.)
includes nominal and ordinal data - answer ✔✔-Categorical data
identify a category (qualitative, attribute, categorical, or classification data and can be coded numerically
like 1 = Apple, 2 = Lenovo) - mathematical operations are performed only with counts or frequencies of
categories (you wouldn't average) - answer ✔✔-Nominal data
data codes can be ranked like 1 = Frequently, 2 = Sometimes, 3 = Rarely - distance between codes is not
meaningful (likert scale) - answer ✔✔-Ordinal data
used in survey research and allow the taker to answer a question with five scaled options like Strongly
Agree, Somewhat Agree, Neutral, etc. - answer ✔✔-Likert Scales
assigns numbers
includes discrete vs continuous and time series vs cross-sectional - answer ✔✔-Numerical data
Discrete data: countable, integer value, observed, counted on hand
Continuous data: fraction or decimal, measured by an instrument, turns into discrete by rounding -
answer ✔✔-Discrete and Continuous data
, Time Series data: each observation in the sample represents a different equally spaced point in time (we
are interested in trends and patterns)
Focuses on the same variable over a period of time
Cross-Sectional data: each observation represents a different individual unit at the same point in time
(VISA balances) and we are interested in variation or relations between them
Focuses on several variables at the same point in time - answer ✔✔-Time Series and Cross-Sectional
data
Population of N Items
Parameters: μ = population mean, π = population proportion
Sample of n Items
Statistics: x = sample mean, p = sample proportion - answer ✔✔-Population vs Sample
Simple Random Sample: use random numbers to select items from a list
Systematic Sample: select every nth item from a list or sequence
Stratified Sample: select randomly within defined strata (age, gender)
Cluster Sample: select random geographical regions that represent the population - answer ✔✔-
Random Sampling Methods
Judgment Sample: use expert knowledge to choose "typical" items
Convenience Sample: use a sample that happens to be available
Focus Groups: in-depth dialog with a representative panel of individuals - answer ✔✔-Non-Random
Sampling Methods
Nonresponse Bias: respondents differ from nonrespondents
Selection Bias: self-selected respondents are atypical
Response Error: respondents give false information
Coverage Error: incorrect specification of frame or population
