1. 1st Semester Final Review Day 1: Exploratory Data Analysis
Hardest title, easiest problems!

2. Graphs – Quantitative Data
Stemplot
Back to Back Stemplot
Calf Weight
Supplement No Supplement
Parts per million ClO2

3. Graphs – Quantitative Data
Boxplot
Histogram
Modified Boxplot

4. Graphs – Quantitative Data
Side by Side Boxplots

5. Graphs – Categorical Data
Pie Chart
Bar Chart
29.0%
46.2%
24.8%
Frequency
Political Identification
Liberal
Moderate
Conservative 20 10 40 30 70 60 50

6. Graphs – Categorical Data
Side by Side Bar Chart
Segmented Bar Chart

7. Describing or comparing distributions
Center – mean, median (generally use median when looking at a graph)
Shape (symmetry/skew, modes/peaks, unusual features)
Spread – standard deviation, range, IQR (generally use range or IQR when looking at a graph)

8. Center Mean: add up and divide by n
Strongly affected by outliers & skew (pulled in the direction of the skew or outliers)
Median: order the numbers and find the middle
Resistant to skew/outliers (not strongly affected)

9. Shape
Approximately Symmetric
Skewed Right
Skewed Left

10. Shape
Unimodal
Bimodal
Multimodal
Uniform

11. Spread Range: Max – Min (affected by outliers)
Quartiles: (resistant to skew/outliers)
Q1 = 25th percentile (median of the bottom half)
Median = 50th percentile
Q3 = 75th percentile (median of the top half)
IQR: Interquartile range = Q3 – Q1
Standard Deviation: average distance of individual values away from the mean
Strongly affected by outliers/skew (not resistant)

12. Are there outliers in a data set?
Outliers are values which are outside the upper or lower fence
Upper fence = Q (IQR)
Lower fence = Q1 – 1.5(IQR)

13. What happens to summary statistics when we…
Add a constant to a data set?
Measures of position (center, minimum, maximum, quartiles) change
Measures of spread (standard deviation, range, IQR) do not change
Multiply a data set by a constant?
Measures of position and measures of spread change

14. Standardized Score
z-score = the number of standard deviations a value falls above or below the mean
For an Individual:

15. Normal Distribution (68-95-99.7 Rule)
Also called the Empirical Rule
Standard deviation = 1st inflection point