Probability and Statistics, WGU C955
Question and answers 100% correct
2026/2027
Boxplot - correct answer an image that has min, Q1, median, Q3, max
Histogram - correct answer A graphical representation -- bars, measuring the frequency within each
interval
Skewed right - correct answer Not a symmetric distribution, the tail is on the right, i.e. extra stuff on the
right
Measures of center - correct answer Median, the mean (and mode)
Measures of spread - correct answer Range, IQR & standard deviation
Standard Deviation Rule - correct answer 68% of the data are within 1 standard deviation, 95% are
within 2, 99.7 are within 3 standard deviations from the mean.
For skewed data, use these for center and spread - correct answer In this situation, we use median (for
center) & IQR (for spread)
Explanatory variable - correct answer In a study, what we think is the "cause"
Response variable - correct answer In a study, what we think is the "effect"
Scatter plot - correct answer A graphical representation of Q -> Q
, Two way table - correct answer A graphical representation of C -> C
Side-by side box - correct answer A graphical representation of C -> Q
Linear relationship - correct answer "shaped like a line"
Correlation coefficient, r - correct answer Between -1 and 1; measures how close the points are to the
line and if the trend is uphill (positive) or downhill (negative).
r = -0.2, for example - correct answer This is an example of a correlation coefficient that represents a
weak negative correlation.
r = 0.9, for example - correct answer This is an example of a correlation coefficient that represents a
strong positive correlation.
Linear regression line - correct answer A line that fits the data as close as possible, used to make
predictions
Interpolation - correct answer Making predictions *within* the range of your data. This is usually
accurate.
Extrapolation - correct answer Making predictions *outside* of the range of your data. This is generally
a bad idea.
Simpson's Paradox - correct answer When split up, each data set can have a pattern which goes away
when all the data is combined.
Question and answers 100% correct
2026/2027
Boxplot - correct answer an image that has min, Q1, median, Q3, max
Histogram - correct answer A graphical representation -- bars, measuring the frequency within each
interval
Skewed right - correct answer Not a symmetric distribution, the tail is on the right, i.e. extra stuff on the
right
Measures of center - correct answer Median, the mean (and mode)
Measures of spread - correct answer Range, IQR & standard deviation
Standard Deviation Rule - correct answer 68% of the data are within 1 standard deviation, 95% are
within 2, 99.7 are within 3 standard deviations from the mean.
For skewed data, use these for center and spread - correct answer In this situation, we use median (for
center) & IQR (for spread)
Explanatory variable - correct answer In a study, what we think is the "cause"
Response variable - correct answer In a study, what we think is the "effect"
Scatter plot - correct answer A graphical representation of Q -> Q
, Two way table - correct answer A graphical representation of C -> C
Side-by side box - correct answer A graphical representation of C -> Q
Linear relationship - correct answer "shaped like a line"
Correlation coefficient, r - correct answer Between -1 and 1; measures how close the points are to the
line and if the trend is uphill (positive) or downhill (negative).
r = -0.2, for example - correct answer This is an example of a correlation coefficient that represents a
weak negative correlation.
r = 0.9, for example - correct answer This is an example of a correlation coefficient that represents a
strong positive correlation.
Linear regression line - correct answer A line that fits the data as close as possible, used to make
predictions
Interpolation - correct answer Making predictions *within* the range of your data. This is usually
accurate.
Extrapolation - correct answer Making predictions *outside* of the range of your data. This is generally
a bad idea.
Simpson's Paradox - correct answer When split up, each data set can have a pattern which goes away
when all the data is combined.
