WGU C955 PROBABILITY AND STATISTICS EXAM / 50 QUESTIONS AND 100% CORRECT ANSWERS LATEST GUIDE 2024.

WGU C955 PROBABILITY AND STATISTICS EXAM / 50 QUESTIONS AND 100% CORRECT ANSWERS LATEST GUIDE 2024. 2 / 6 1. Boxplot: an image that has min, Q1, median, Q3, max 2. Histogram: A graphical representation -- bars, measuring the frequency within each interval 3. Skewed right: Not a symmetric distribution, the tail is on the right, i.e. extra stuff on the right 4. Measures of center: Median, the mean (and mode) 5. Measures of spread: Range, IQR & standard deviation 6. 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. 7. For skewed data, use these for center and spread: In this situation, we use median (for center) & IQR (for spread) 8. Explanatory variable: In a study, what we think is the "cause" 9. Response variable: In a study, what we think is the "effect" 10. Scatter plot: A graphical representation of Q -> Q 11. Two way table: A graphical representation of C -> C 12. Side-by side box: A graphical representation of C -> Q 13. Linear relationship: "shaped like a line" 14. 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). 15. r = -0.2, for example: This is an example of a correlation coefficient that represents a weak negative correlation. 16. r = 0.9, for example: This is an example of a correlation coefficient that repre- sents a strong positive correlation. 17. Linear regression line: A line that fits the data as close as possible, used to make predictions 18. Interpolation: Making predictions *within* the range of your data.Thisis usually accurate. 19. Extrapolation: Making predictions *outside* of the range of your data.This is generally a bad idea. 20. Simpson's Paradox: When split up, each data set can have a pattern which goes away when all the data is combined. 21. Only way to prove causation: Experiments, because they account for lurking variables 22. Observational study: A type of study where we measure or survey members of a sample without 3 / 6 trying to affect them. Cannot prove causation. 23. Experimentalstudy: A study where you splitsubjects up randomly and impose a change on one group to study the effect; can prove causation 24. Prospective study: Is a study that's done over time to find results / A study watching for outcomes during the study period