Median
The median is another measure of central tendency. It is the middle value of a given set of measurements, when the values or measurements are arranged in an array.

An array is an arrangement of values in increasing or decreasing order.

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Characteristics of the Mean

Below are the characteristics of the mean of any distribution:
1. The mean is the most appropriate measure of central tendency when the data are in the interval or ratio scale.
2. The mean lies between the largest and smallest values or measurements.
3. There is only one value for the mean for a given set of values or measurements.
4. The mean is easily influenced by extreme values because all values contribute to the average. If there are high values, the mean tends to be high also. If there are extremely low values, the mean tends to be low also.

4.1 Coded Formula
The computation of the mean can be facilitated by using the coded formula which is shown below:

where:
X_am = assumed mean
f = frequency
d = coded deviation
n = total frequency
i = class size

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The Classmark Formula

The formula for the mean using the classmark is as follows:

where:
x = measurement or score
f = frequency
X = classmark
n = total frequency

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Mean for Grouped Data
To compute the mean for grouped data, we can use two formulas, namely:
1. The Classmark Formula, and
2. The Coded Formula.