ICS Statistics part 1 chapter 1 Definitions (page 2)

Descriptive Statistics:

                        It is the branch of statistics which deals with the methods and principles of data collection and their presentation in meaningful form.

Inferential Statistics:

It is the branch of statistics which deals with the methods and procedures of drawing conclusion about the population on the basis of information obtained from the sample.

Variable:

                        Any characteristic that varies from one individual or an object to another.

Or

                       Any quantity that can be changed is called variable. For example age, height of students, number of children. A variable is denoted by x, y or z etc.

Constant:

                       Any quantity that can not be changed is called constant. For example 5, 12, ℮, п, etc.

Quantitative Variable:

                        If a variable can assume a numerical value is called quantitative variable. For example height, weight, number of students, etc. Quantitative variable is also called attribute of categorical variable.

Qualitative Variable:

                        If a variable can not assume a numerical value is called qualitative variable. For example eye colour, body colour, sex, intelligence, honesty, etc.

Types of Quantitative variable:

                                      It has two main types:

1.                              Discrete Variable

2.                              Continuous Variable

Discrete Variable:

                        A variable is called discrete if it can take values in whole numbers. A discrete variable represents countable data. For example number of children in a family, number of fans, etc.

Continuous Variable:

                        A variable is called continuous if it can take all possible values within an interval. A continuous variable represents measurable data. For example height and weight of students, temperature, etc.