SDS 306 Final Exam Questions and
Correct Answers, 112Q&A. 2025/2026.
100% Verified.
Data
the set of scores of a particular variable
Quantitative
a type of variable where the values are numerical measurements with units
categorical
type of variable where the values designate different categories
coding
assigning a value to data to show which category it belongs to
marginal distribution
the distribution of either variable alone- can be counts or percentages
frequency
the number of times a value is observed in a dataset
bar graph
graphical display for categorical data, with data groups in categories
histogram
graphical display for quantitative data, with data grouped in bins
relative frequency
a proportion (number of observations out of the total observations)
median and IQR
What is the correct measure of center and spread for skewed data?
mean and standard deviation
What is the correct measure of center and spread for symmetric data?
minimum, Q1, median, Q3, maximum
What is the 5 number summary?
<Q1-1.5(IQR), >Q3+1.5(IQR)
What are the outlier formulas?
, variance
the sum of squared deviations from the mean divided by (n-1)
standard deviation
square root of the variance (typical distance of scores from the mean)
centrality, spread, symmetry, tail length
Boxplots are indicators of what?
measures of position change but measures of spread stay the same
What happens when you add or subtract from data?
measure of position and spread both change
What happens when you multiply or divide a constant to data?
-1 to 1
What is the possible range of values for the correlation coefficient?
quantitative variable condition, straight enough condition, no outlier conidtion
What are the assumptions/conditions for correlation?
scatterplot
a display of the relationship between 2 quantitative variables
lurking variable
variable other then x and y that simultaneously affects both variables, accounting for the correlation
between the two
explanatory variable
x-variable, independent variable, variable that is responsible for y- variable
response variable
y-variable, dependent variable, what you to hope to predict or explain
quantitative variables condition, straight enough condition, no outlier condition, does the plot
thicken?
What are the assumptions/ conditions for regression?
if the scatter aroudn the line of best fir either decreases or increases as you go along the x-axis and if
the residual plot has a fan shape
When is the "does the plot thicken?" condition violated?
leverage
when the x-coordinate of a point is much different than the mean of the x's
influence
Correct Answers, 112Q&A. 2025/2026.
100% Verified.
Data
the set of scores of a particular variable
Quantitative
a type of variable where the values are numerical measurements with units
categorical
type of variable where the values designate different categories
coding
assigning a value to data to show which category it belongs to
marginal distribution
the distribution of either variable alone- can be counts or percentages
frequency
the number of times a value is observed in a dataset
bar graph
graphical display for categorical data, with data groups in categories
histogram
graphical display for quantitative data, with data grouped in bins
relative frequency
a proportion (number of observations out of the total observations)
median and IQR
What is the correct measure of center and spread for skewed data?
mean and standard deviation
What is the correct measure of center and spread for symmetric data?
minimum, Q1, median, Q3, maximum
What is the 5 number summary?
<Q1-1.5(IQR), >Q3+1.5(IQR)
What are the outlier formulas?
, variance
the sum of squared deviations from the mean divided by (n-1)
standard deviation
square root of the variance (typical distance of scores from the mean)
centrality, spread, symmetry, tail length
Boxplots are indicators of what?
measures of position change but measures of spread stay the same
What happens when you add or subtract from data?
measure of position and spread both change
What happens when you multiply or divide a constant to data?
-1 to 1
What is the possible range of values for the correlation coefficient?
quantitative variable condition, straight enough condition, no outlier conidtion
What are the assumptions/conditions for correlation?
scatterplot
a display of the relationship between 2 quantitative variables
lurking variable
variable other then x and y that simultaneously affects both variables, accounting for the correlation
between the two
explanatory variable
x-variable, independent variable, variable that is responsible for y- variable
response variable
y-variable, dependent variable, what you to hope to predict or explain
quantitative variables condition, straight enough condition, no outlier condition, does the plot
thicken?
What are the assumptions/ conditions for regression?
if the scatter aroudn the line of best fir either decreases or increases as you go along the x-axis and if
the residual plot has a fan shape
When is the "does the plot thicken?" condition violated?
leverage
when the x-coordinate of a point is much different than the mean of the x's
influence
