Definition: The median is a value that divides an ordered dataset into two equal parts, with 50% of values below and 50% above.

Example: A series of numbers (7, 8, 8, 8, 9, 10, 10, 11, 11, 12, 12, 13, 13, 13) was used to demonstrate median calculation.

Definition: The range is the difference between the largest and smallest values in a dataset.

Example: Using a student's grades to demonstrate range calculation (20 - 5 = 15).

Highlight: The median provides a measure of central tendency that is less sensitive to extreme values than the mean.

Definition: The frequency (effectif) of a data point is the number of times it appears in a dataset. The total frequency is the sum of all frequencies.

Example: In a class test, the following grades were recorded: 6 (3 times), 8 (3 times), 10 (6 times), 12 (7 times), 16 (4 times), and 18 (1 time), totaling 24 students.

Definition: Relative frequency is calculated by dividing the frequency of a value by the total frequency. It can be expressed as a fraction, decimal, or percentage.

Highlight: The sum of all relative frequencies must equal 1 (or 100%).

Example: In a dice-rolling experiment with 20 throws, results were organized in a frequency table showing both absolute frequencies and percentages for each outcome.