PROBABILITY AND STATISTICS, WGU
C955 CORRECT 100%
Boxplot - ANSWERan image that has min, Q1, median, Q3, max
Histogram - ANSWERA graphical representation -- bars, measuring the frequency
within each interval
Skewed right - ANSWERNot a symmetric distribution, the tail is on the right, i.e. extra
stuff on the right
Measures of center - ANSWERMedian, the mean (and mode)
Measures of spread - ANSWERRange, IQR & standard deviation
Standard Deviation Rule - ANSWER68% 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 - ANSWERIn this situation, we use
median (for center) & IQR (for spread)
Linear regression line - ANSWERA line that fits the data as close as possible, used to
make predictions
Interpolation - ANSWERMaking predictions *within* the range of your data. This is
usually accurate.
Extrapolation - ANSWERMaking predictions *outside* of the range of your data. This is
generally a bad idea.
Simpson's Paradox - ANSWERWhen split up, each data set can have a pattern which
goes away when all the data is combined.
Only way to prove causation - ANSWERExperiments, because they account for lurking
variables
Observational study - ANSWERA type of study where we measure or survey members
of a sample without trying to affect them. Cannot prove causation.
Experimental study - ANSWERA study where you split subjects up randomly and
impose a change on one group to study the effect; can prove causation
Prospective study - ANSWERIs a study that's done over time to find results / A study
watching for outcomes during the study period
C955 CORRECT 100%
Boxplot - ANSWERan image that has min, Q1, median, Q3, max
Histogram - ANSWERA graphical representation -- bars, measuring the frequency
within each interval
Skewed right - ANSWERNot a symmetric distribution, the tail is on the right, i.e. extra
stuff on the right
Measures of center - ANSWERMedian, the mean (and mode)
Measures of spread - ANSWERRange, IQR & standard deviation
Standard Deviation Rule - ANSWER68% 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 - ANSWERIn this situation, we use
median (for center) & IQR (for spread)
Linear regression line - ANSWERA line that fits the data as close as possible, used to
make predictions
Interpolation - ANSWERMaking predictions *within* the range of your data. This is
usually accurate.
Extrapolation - ANSWERMaking predictions *outside* of the range of your data. This is
generally a bad idea.
Simpson's Paradox - ANSWERWhen split up, each data set can have a pattern which
goes away when all the data is combined.
Only way to prove causation - ANSWERExperiments, because they account for lurking
variables
Observational study - ANSWERA type of study where we measure or survey members
of a sample without trying to affect them. Cannot prove causation.
Experimental study - ANSWERA study where you split subjects up randomly and
impose a change on one group to study the effect; can prove causation
Prospective study - ANSWERIs a study that's done over time to find results / A study
watching for outcomes during the study period
