WGU C955 – Probability and Statistics. A+
Graded End Term Exam
Unbalanced response - ✔✔Giving more options that are negative than positive options (or vice versa)
which biases the responses towards the more common option
Matched pairs - ✔✔Grouping two similar subjects and giving different treatments/procedures to each in
order to compare the differences. For example, having one twin take a medication while the other twin
does not.
Blind experimental study - ✔✔When information of a study isn't revealed to the participants
Double Blind Study - ✔✔When information of study is hidden from the researcher and the participant.
Population - ✔✔The entire group you are trying to describe or understand.
Sampling frame - ✔✔List of group from which you choose your sample.
Sample - ✔✔The group that is actually picked to be included in a study
Simple random sample - ✔✔making a selection by following a random pattern and selecting without
replacement. Unbiased.
Boxplot - ✔✔an image that has min, Q1, median, Q3, max
Histogram - ✔✔A graphical representation -- bars, measuring the frequency within each interval
Skewed right - ✔✔Not a symmetric distribution, the tail is on the right, i.e. extra stuff on the right
Measures of center - ✔✔Median, the mean (and mode)
, Measures of spread - ✔✔Range, IQR & standard deviation
Standard Deviation Rule - ✔✔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 - ✔✔In this situation, we use median (for center) &
IQR (for spread)
Explanatory variable - ✔✔In a study, what we think is the "cause"
Response variable - ✔✔In a study, what we think is the "effect"
Scatter plot - ✔✔A graphical representation of Q -> Q
Two way table - ✔✔A graphical representation of C -> C
Side-by side box - ✔✔A graphical representation of C -> Q
Linear relationship - ✔✔"shaped like a line"
Correlation coefficient, r - ✔✔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 - ✔✔This is an example of a correlation coefficient that represents a weak negative
correlation.
r = 0.9, for example - ✔✔This is an example of a correlation coefficient that represents a strong positive
correlation.
Graded End Term Exam
Unbalanced response - ✔✔Giving more options that are negative than positive options (or vice versa)
which biases the responses towards the more common option
Matched pairs - ✔✔Grouping two similar subjects and giving different treatments/procedures to each in
order to compare the differences. For example, having one twin take a medication while the other twin
does not.
Blind experimental study - ✔✔When information of a study isn't revealed to the participants
Double Blind Study - ✔✔When information of study is hidden from the researcher and the participant.
Population - ✔✔The entire group you are trying to describe or understand.
Sampling frame - ✔✔List of group from which you choose your sample.
Sample - ✔✔The group that is actually picked to be included in a study
Simple random sample - ✔✔making a selection by following a random pattern and selecting without
replacement. Unbiased.
Boxplot - ✔✔an image that has min, Q1, median, Q3, max
Histogram - ✔✔A graphical representation -- bars, measuring the frequency within each interval
Skewed right - ✔✔Not a symmetric distribution, the tail is on the right, i.e. extra stuff on the right
Measures of center - ✔✔Median, the mean (and mode)
, Measures of spread - ✔✔Range, IQR & standard deviation
Standard Deviation Rule - ✔✔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 - ✔✔In this situation, we use median (for center) &
IQR (for spread)
Explanatory variable - ✔✔In a study, what we think is the "cause"
Response variable - ✔✔In a study, what we think is the "effect"
Scatter plot - ✔✔A graphical representation of Q -> Q
Two way table - ✔✔A graphical representation of C -> C
Side-by side box - ✔✔A graphical representation of C -> Q
Linear relationship - ✔✔"shaped like a line"
Correlation coefficient, r - ✔✔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 - ✔✔This is an example of a correlation coefficient that represents a weak negative
correlation.
r = 0.9, for example - ✔✔This is an example of a correlation coefficient that represents a strong positive
correlation.
