ABSTRACT
Some basic concepts of mathematics are considered prerequisites to un derstand statistics. The subject of statistics deals with variables whose val ues vary from one to the other. Variation is studied using different statistical tools. For example, consider that an economist intends to study the income distribution in different families. It would be cumbersome to mention the characteristic frequently during the course of his or her investigation and hence it is imperative that we identify the variable by some algebraic nota tion. The variable under study (e.g., income) varies from one family to the other. Hence, income is called the variable, in statistical terminology. It is denoted by the letter x. If the incomes (in thousands of U.S. dollars) of the ten families are 4, 10, 5, 3, 20, 8, 7, 6, 7, and 10, then the incomes of the dif ferent families are referred to as follows:
In general the set of observations are denoted by .v,, v2. . . ,vl0, and .v, re fers to the income of the first family, and so on. Generally, the size of the sample families is denoted by the letter/; and the values by.v,,.v2.. ..v,__ vn.
