How to Work out Interquartile Range: Summary

Types of Data

1. Data Introduction: The Lady with the Lamp
2. Quantitative and Qualitative Variables
3. Continuous and Discrete Variables
4. What are Data?
5. Types of Data
6. Introduction
7. Frequency Tables
8. Frequency Tables and Quantitative Data
9. Grouped Frequency Tables
10. Parts of the Grouped Frequency Table
11. Hidden Boundaries
12. Finding Class Boundaries
13. Grouped Frequency Tables with Boundaries
14. Class Widths and Midpoints

Linear Interpolation

1. Finding Unknown Points
2. Linear Interpolation
3. Linear Interpolation and Tables
4. Reading Grouped Frequency Tables
5. Cumulative Frequency Counts
6. Interpolating Frequency Counts in Subclasses
7. Interpolating Frequency Counts- Shortcuts

Descriptive Statistics – Introduction

1. Introduction
2. Descriptive Statistics
3. Frequency Diagrams
4. Distribution
5. Central Location and Spread

Measures of Central Location

1. Central Location – Mode
2. The Modal Class Interval
3. More Measures of Central Location
4. The Total Number of Data Points
5. Sigma Notation
6. Central Location – Mean
7. Sigma Notation Part 2
8. Calculating a Mean from Frequency Tables
9. Estimating a Mean from Grouped Frequency Tables
10. Central Location – Median
11. Describing the Location of the Median
12. Finding the Median in a Large Data Set
13. Central Tendency and Symmetric Distributions
14. Positively and Negatively Skewed Distributions

Measures of Spread

1. The Problem with Range
2. Quartiles
3. The Interquartile Range
4. How do we cut data into quarters?
5. Finding the Position of Quartiles
6. Rounding the Position of Quartiles (Article)
7. The Values of Quartiles Between Data Points
8. Finding Quartiles from Frequency Tables
9. Finding Quartiles of Continuous Data
10. Another Measure of Location
11. Percentiles
12. Percentiles and Quartiles
13. Finding the Position of Percentiles
14. Spread – The Interpercentile Range
15. What’s So Great About Interpercentile Ranges?

Outliers and Standard Deviation

1. Introduction: Outliers
2. Dealing with Outliers
3. Strategy 1: Finding Outliers Using Quartiles (Part 1)
4. Strategy 1: Finding Outliers Using Quartiles (Part 2)
5. Strategy 1: The Constant k
6. Another Strategy for Finding Outliers
7. Deviation
8. Finding the Average Deviance
9. Step 1: Sxx
10. Step 2: Variance
11. Step 3: Standard Deviation
12. Strategy 2: Finding Outliers Using Standard Deviation
13. Mean Absolute Deviation
14. Removing Anomalies
15. SD and Variance: Measures of Spread
16. Finding Variance/SD: A Shortcut Part 1
17. Finding Variance/SD: A Shortcut Part 2
18. Finding the Variance/SD from a Frequency Table
19. Finding the Variance/SD from a Grouped Frequency Table
20. Comparing Data Sets

Coding

1. Introduction to Coding
2. Coding Data
3. Rules for Coding Data
4. Rules Involving Subtraction
5. Rules Involving Subtraction and Division
6. Decoding Data
7. Finding the Mean of Coded Data
8. Finding the Standard Deviation of Coded Data
9. How Mean and Standard Deviation are Affected by Coding

Box Plots and Cumulative Frequency Diagrams

1. Introduction to Descriptive Statistics
2. Box Plots
3. Box Plots with Outliers
4. Comparing Box Plots
5. Another Way to Estimate Data
6. Plotting Cumulative Frequency Diagrams
7. Reading Cumulative Frequency Diagrams

Histograms and Frequency Polygons

1. Introduction To Histograms
2. Why is a Histogram Not a Bar Chart? – Part 1
3. Why is a Histogram Not a Bar Chart? – Part 2
4. Why Do Histograms Use Area to Represent Frequency?
5. Plotting A Histogram – Part 1
6. Plotting A Histogram – Part 2
7. Histogram Questions – Part 1
8. Histogram Questions – Part 2
9. Frequency Polygons

Sampling

1. Introduction to Inferential Statistics
2. What is a Population?
3. What is a Census?
4. Censuses: Pros and Cons
5. Samples and Inferences
6. Why is it Called a Sampling Frame?
7. Samples Should Be Representative
8. Sample Size
9. Types of Sampling
10. Opportunity Sampling
11. Opportunity Sampling: Pros and Cons
12. Quota Sampling
13. Quota Sampling: Pros and Cons
14. Random Sampling vs Non-Random Sampling
15. Simple Random Sampling
16. Simple Random Sampling: Pros and Cons
17. Systematic Sampling
18. Systematic Sampling: Pros and Cons
19. Stratified Sampling
20. Stratified Sampling: Pros and Cons