Some explanations to build intervals
*Why do we need to build intervals?
-Sometimes, we have a short number of data and their corresponding frequencies :
For example: 5- 8- 10- 12- 16 - 32
With frequencies: f1.- f2 - f3 - f4-- f5 - f6
But……………………………………….
Often, we have many data and their corresponding frequencies: With 20 or more dates, it is
necessary to build intervals.
Building intervals require a procedure:
-Building intervals require a procedure :
1) Choose the number of intervals you want to build ( 5- 15).
2) Calculate the range ( See the formula).
3) Determine the Interval width.
…..and two states:
4) Be relaxed.
5) Have intuition.