Chapter 3.3: Percentiles and Box Plots - Healthcare Perspective
Channel: Monika Wahi
Date: 2015-10-03

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In this video, Monika Wahi lectures to Laboure College students in her Essentials of Statistics class. 
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I listed the links I mention below as they come up in the lecture. Enjoy!

00:15 Learning objectives for the lecture
00:52 Topics we will cover in lecture
01:26 Example of percentiles to help you understand what they are
03:38 Formal definition of percentiles
05:30 Formal definition of quartiles
06:35 How to calculate quartiles by hand: Four steps
06:39 Step 1: Order data smallest to largest
06:49 Step 2: Find the median
07:03 Step 3: Find the median of lower half of data
07:24 Step 4: Find the median of the upper half of data
07:44 Discussion of range vs. interquartile range
08:11 Definition of interquartile range (IQR)
08:32 Example of computing quartiles
08:41 Site Monika collected data from: https://www.ahd.com/ 
08:51 Monika describes how she sampled data for example (sampling lecture: https://youtu.be/wNwK34GcmiQ )
09:14 Step 1 Example: Order the data
09:33 Step 2 Example: Find median (lecture about medians: https://youtu.be/wRYCT4V3p9w )
10:31 Step 3 Example: Find median of lower half
11:10 Step 4 Example: Find median of upper half
11:35 How to calculate IQR
12:14 Finding quartiles if we start with an even number of values (e.g., 6)
13:56 Finding quartiles if we start with an odd number of values (e.g., 7 or 11 values)
14:38 Finding quartiles with 8 values is different than with 6, even though these are both even numbers
16:16 Finding quartiles if we start with 9 values
17:02 Summary of process to approach median and quartile calculations
17:33 Begin discussion of box-and-whisker plots
17:48 Box plot “ingredients” – numbers needed for box plot
18:34 Drawing a blank graph for a box plot
19:27 Draw a line for Quartile 1 on the graph
20:05 Draw a line for Quartile 3 on the graph
20:50 Connect the lines vertically
21:02 Draw a line for Quartile 2 (the median)
21:33 Draw in the whiskers for the minimum and maximum
22:26 Connect the whiskers
22:36 Viewing a graph of the interquartile range
23:06 Assessing distributions of data using box-and-whisker plots
23:22 How to make stem-and-leaf diagrams: https://youtu.be/zW-1nhR3es8 and how to make histograms: https://youtu.be/yJr5nwdQjd0 
23:41 Skewed right box plot example
24:08 Skewed left box plot example
24:15 Normal distribution box plot examples
24:48 Comparison of box plot to roller coaster flyover
25:44 Relationship of histogram to box plot in terms of graphing distributions
25:49 Review of topics covered in lecture

Chapter 3.3: Percentiles and Box Plots - Healthcare Perspective