Probability And Statistics, Wgu C955 Already Passed

Experimenter effect {Ans: When the persons running an experiment affects its results by influencing the subjects inadvertently}For independent events, P(A and B) = ? {Ans: P(A)*P(B)}Simpson's Paradox {Ans: When split up, each data set can have a pattern which goes away when all the data is combined.}In general, P(A and B) = ? {Ans: P(A)*P(B|A)}r = 0.9, for example {Ans: This is an example of a correlation coefficient that represents a strong positive correlation.}Response variable {Ans: In a study, what we think is the "effect"}r = -0.2, for example {Ans: This is an example of a correlation coefficient that represents a weak negative correlation.}Simple random sample {Ans: making a selection by following a random pattern and selecting without replacement. Unbiased.}For skewed data, use these for center and spread {Ans: In this situation, we use median (for center) & IQR (for spread)}P(A or B) = ? {Ans: P(A) + P(B) - P(A and B)}Population {Ans: The entire group you are trying to describe or understand.}The formula for all simple probabilities {Ans: (number of possible outcomes for the specific event) / (total number of possible outcomes)}Placebo effect {Ans: A