WGU C955 Formulas and Terms (Latest 2023/ 2024 Update) Applied Probability and Statistics | Questions and Verified Answers| 100% Correct

WGU C955 Formulas and Terms (Latest 2023/ 2024 Update) Applied Probability and Statistics | Questions and Verified Answers| 100% Correct Q: Simpsons Paradox A counterintuitive situation that occurs when a result that appears in individual groups of data disappears or reverses when the groups are combined. Can only occur when the sizes of the groups are inconsistent Q: Lurking Variables : Answer: • A lurking variable is a variable not included in the study, but affects the variables that were included in the study• Never assume that a causation exists just because there is an association between two variables - always be on the lookout for lurking variables Q: Causation Answer: A change in one variable creates a change in the other variable.o Can only be determined from an experiment Q: Association Answer: means there is a relationship between two variables.Association does not necessarily imply causation. o We can use scatterplots to visualize the data and determine if there is at least an association, but we cannot determine causation from a scatterplot alone.o Can establish association through an observational study. Q: Observational Study Answer: There are no treatment or control groups because the participants self-select their groups. Researchers observe if there is an association between variables. Q: Experimental Study Answer: - Researchers randomly assign participants to two or more groups. One group is designated as a control group where no treatment (placebo) is given while all other groups are given treatments to determine if there is causation between variables. Q: Graphical Displays: Answer: Just C - Pie chart or bar chart• Just Q - Histogram, stem plot, boxplot, or dot plot• C ’ C - Two-way table with Conditional Percentages• C ’ Q - Side-by-side boxplot with 5-number summary• Q ’ Q - Scatterplot with correlation coefficient Q: Correlation Coefficient (Q ’ Q) Answer: Strength: On a scatterplot, the closer the points are laid out in a line,the stronger the correlation. measures the direction and strength of the linear relationship between the variables The closer r is to +1, the stronger the positive correlation. The closer r is to -1, the stronger the negative correlation. The closer r is to 0, the weaker the correlation. Q: Positive Correlation Answer: scatterplot reveals an "uphill trend." as the explanatory variable increases, the response variable increases. Q: Negative Correlation Answer: scatterplot reveals a "downhill trend."As the explanatory variable increases, the response variable decreases. Q: No Correlation- Answer: scatterplot reveals no trend between the variables Q: Variable Type Q ’ Q Answer: Graphical Display: Scatterplot Numerical Measure: Correlation Coefficient (r value) Q: Variable Type C ’ Q Answer: Graphical Display: Side by Side Boxplots Numerical Measure: Five Number Summary Q: Variable Type C ’ C Answer: Graphical Display: Two Way Table Numerical Measure: Conditional Percentages Q: Explanatory Variable Answer: Influences the response variable. Q: Response Variable Answer: Is affected by the explanatory variable. Q: Standard Deviation Rule Answer: 68% of the data is within 1 standard deviation of the mean.• 95% of the data is within 2 standard deviations of the mean.• 99.7% of the data is within 3 standard deviations of the mean Q: Mode - Answer: value that occurs most often in a data set Q: Median halfway point, equal number of data points above the median as below, always order the data from smallest to largest first Q: Mean