Data can also be presented by using tables. Important features and significant values are easily observed when data are presented in a tabular form. Moreover, comparisons are also easily made.

Parts of a Table:

1. Table number - for easy reference to the table
2. Table title - briefly explains the content of the table
3. Column header - describes the data in each column
4. Row classifier - shows the classes or categories
5. Body - main part of the table
6. Source note - placed below the table when the data presented are not original

Example:

Frequency distribution table - shows the data arranged into different classes and the frequency of each class

note: frequency - number of times a value or class occurs

Example:

The row classifiers 66 - 70, 71 - 75, 76 - 80… 96 - 100 are called class intervals. The minimum values in each class (66, 71, 76, …96) are called lower limits (LL). The highest values in each class are called upper limits (UL).

The class interval size or class width (i) is the number of values within a class. In the example, i = 5 (66, 67, 68, 69, 70; 71, 72, 73, 74, 75). This is obtained by manually counting the number of values within a class or by using the following formula:

The example above is a simple frequency distribution table because it consists one the class interval and its frequencies.

On the other hand, a complete frequency distribution table also contains a column with the class marks or midpoint (X) and class boundaries (cb).

Example:

The succeeding class marks may be obtained by adding i to the first class mark.

Example:

The class boundaries are always one decimal value more than the recorded values. So for whole number values (like in the Examples), the class boundaries are up to the tenths place. Class boundaries are always one-half unit less than the LL and one-half unit more than the LL.

Example: One-half unit of a whole number is 0.5, thus…

When constructing a frequency distributiontable, the number of data should be treated as the guide. The following are some steps to follow:

1. Decide on the number of classes.
2. Determine the class width (i):
   note: i should have decimal places as the data
3. Always start with the lowest values and the lowest class.
4. Tally the frequencies for each class, until the highest value is reached.
5. The last call interval may exceed the highest value, as long as the i is followed.

Example:
Contruct a frequency distribution table with 7 classes for the data given in the Textual Method Example.

1. Decide on the number of classes: 7 (instruction)
2. Determine the class width (i):
   
3. Always start with the lowest values and the lowest class:
   
4. Tally the frequencies for each class, until the highest value is reached

Relative Frequency distribution table - lists the relative frequencies (rf) of the classes

where:
rf = relative frequency
f = frequency
N = total frequency

Example: for class 66 - 70…

Cumulative Frequency distribution table - shows the number of cases falling below (cf) a particular value

The Less Than Cumulative Frequency < cf of the first (lowest) class is its frequency. The < cf of the next class is the sum of < cf of the preceding class and the class' frequency. The < cf of the last class is always equal to the total frequency.

Example: for Table 3…

The Greater Than Cumulative Frequency > cf of the first (lowest) class is the total frequency. The > cf of the next class is the difference between >cf of the preceding class and the preceding class’ frequency. The > cf of the last class is always equal to the frequency of the last (greatest/highest) class.

Example: for Table 3…