3.3. Exploratory Data Analysis

1. Five-Number Summary:

The five number summary can provide important information about both the location and the

dispersion of the data. They are:

Smallest value

First quartile

Median

Third quartile

Largest value

Example 2 (continue):

The original data (in hours) are:

Factory 1: 10.1, 9.9, 10.1, 9.9, 9.9, 10.1, 9.9, 10.1, 9.9, 10.1

Factory 2: 16, 5, 7, 14, 6, 15, 3, 13, 9, 12.

The five-number summary for the data from both factories is

	Smallest		Median		Largest
Factory 1	9.9	9.9	10	10.1	10.1
Factory 2	3	6	10.5	14	16

2. Box Plot:

The box-plot is commonly used graphical method to provide information about both the location

and dispersion of the data. Especially, as the interest is the comparison of the data from different

populations, the box-plot can provide insight. The box-plot is

Note: data outside upper limit and lower limit are called outliers.

JavaStatSoft:

Data summary:

Statistics -> Exploratory Data Analysis -> Quantitative Data