Grouped Frequency Distribution
Grouped Frequency Distribution is used when the range of the data set is large; the
data must be grouped into classes whether it is categorical or interval data. For interval
data, the class is more than one unit in width.
To make a grouped frequency distribution, there are steps to follow in constructing
an FDT.
Steps in Constructing the Grouped Frequency Distribution Table
Step 1. Determine the range ( R ) of the data. The range is the difference between the
highest and lowest scores in the data.
R = HS - LS
Step 2. Determine the number of classes (k).
There are two ways of finding k;
Rule 1: To determine the number of classes use the smallest positive integer k such
that 2k≥n2k≥n, where n is the total number of observations and k is any real number.
Rule 2: The value of k can be solved using the formula
k = 1 + 3.322 ( log of the total number of observations)
Step 3. Determine the class size ( i ) by dividing the range by the desired number of
classes ( k ).
i=Rki=Rk
Grouped Frequency Distribution is used when the range of the data set is large; the
data must be grouped into classes whether it is categorical or interval data. For interval
data, the class is more than one unit in width.
To make a grouped frequency distribution, there are steps to follow in constructing
an FDT.
Steps in Constructing the Grouped Frequency Distribution Table
Step 1. Determine the range ( R ) of the data. The range is the difference between the
highest and lowest scores in the data.
R = HS - LS
Step 2. Determine the number of classes (k).
There are two ways of finding k;
Rule 1: To determine the number of classes use the smallest positive integer k such
that 2k≥n2k≥n, where n is the total number of observations and k is any real number.
Rule 2: The value of k can be solved using the formula
k = 1 + 3.322 ( log of the total number of observations)
Step 3. Determine the class size ( i ) by dividing the range by the desired number of
classes ( k ).
i=Rki=Rk
