PROBABILITY AND STATISTICS , WGU C955 |100 %
VERIFIED AND UPDATED QUESTIONS AND ANSWERS |
100% GUARANTEE PASS| GRADED A+ WELL REVISED
AND RATIONALIZED|LATEST EXAM AND NEWEST
VERSION!!!
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.
Only way to prove causation
CORRECT ANSWER:
Experiments, because they account for lurking variables
Observational study
CORRECT ANSWER:
A type of study where we measure or survey members of a sample
without trying to affect them. Cannot prove causation.
Experimental study
CORRECT ANSWER:
A study where you split subjects up randomly and impose a change
on one group to study the effect; can prove causation
Prospective study
CORRECT ANSWER:
Is a study that's done over time to find results / A study watching for
outcomes during the study period
Retrospective study
CORRECT ANSWER:
A study that looks backwards to assess outcomes and possible
causes after the fact
Control group
CORRECT ANSWER:
VERIFIED AND UPDATED QUESTIONS AND ANSWERS |
100% GUARANTEE PASS| GRADED A+ WELL REVISED
AND RATIONALIZED|LATEST EXAM AND NEWEST
VERSION!!!
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.
Only way to prove causation
CORRECT ANSWER:
Experiments, because they account for lurking variables
Observational study
CORRECT ANSWER:
A type of study where we measure or survey members of a sample
without trying to affect them. Cannot prove causation.
Experimental study
CORRECT ANSWER:
A study where you split subjects up randomly and impose a change
on one group to study the effect; can prove causation
Prospective study
CORRECT ANSWER:
Is a study that's done over time to find results / A study watching for
outcomes during the study period
Retrospective study
CORRECT ANSWER:
A study that looks backwards to assess outcomes and possible
causes after the fact
Control group
CORRECT ANSWER:
