data in hand. The temptation in analyzing the above income data is to at tempt to make generalizations beyond the data in hand, in particular about the distribution of income in the US (not just 23000 households in US). This, how- ever, is not possible in the descriptive statistics framework. In order to be able to generalize beyond the data in hand we need to model"the distribution of income in the US and not just describe the observed data in hand. Such a general model is provided by probability theory to be considered in Section 2 It turns out that the model provided by probability theory owns a lot to the earlier developed descriptive statistics. In particular, most of the concepts which form the basis of the probability theory were motivated by the descriptive statistic concept considered above. The concepts of measures of location, dispersion and shape, as well as the frequency curve, were transplanted into probability theory with renewed interpretations. The frequency curve when reinterpreted becomes a density function purporting to model observable real world phenomena, As for the various measures, they will now be reinterpreted in terms of the density functiondata in hand. The temptation in analyzing the above income data is to at￾tempt to make generalizations beyond the data in hand, in particular about the distribution of income in the US (not just 23000 households in US). This, how￾ever, is not possible in the descriptive statistics framework. In order to be able to generalize beyond the data in hand we need to ”model” the distribution of income in the US and not just describe the observed data in hand. Such a general model is provided by probability theory to be considered in Section 2. It turns out that the model provided by probability theory owns a lot to the earlier developed descriptive statistics. In particular, most of the concepts which form the basis of the probability theory were motivated by the descriptive statistic concept considered above. The concepts of measures of location, dispersion and shape, as well as the frequency curve, were transplanted into probability theory with renewed interpretations. The frequency curve when reinterpreted becomes a density function purporting to model observable real world phenomena, As for the various measures, they will now be reinterpreted in terms of the density function. 3