ABSTRACT
Statistics can be regarded as a body of methods used to summarise data and to draw conclusions from the data. Population is the set of things one wishes to study and should have at least one attribute in common. In practice one seldom, if ever, works on a population due to reasons of: impracticability, financial limitations, and time limitations. There are several types of attributes, discrete and continuous. For a better understanding of the dataset it can be rearranged as an array. An array is the arrangement of the observations according to size. The data are cumbersome and can be further refined as a frequency table. In a frequency table the observations are grouped into different class intervals. Arithmetic mean is the number most commonly used to describe the centre of the distribution. Mean absolute deviation of the observations tells how far ‘on average’ the individual observations are from the arithmetic mean of the set of data.
