# Some Basic Definitions in Statistics

Constant:

A quantity which can be assuming only one value is called a constant. It is usually denoted by the first letters of alphabets $a,b,c$.
For Example: Value of $\pi = \frac{{22}}{7} = 3.14159...$ and value of $e = 2.71828...$.

Variable:

A quantity which can vary from one individual or object to and other is called a variable. It is usually denoted by the last letters of alphabets $x,y,z$.

For Example: Heights and Weights of students, Income, Temperature, No. of Children in a family etc…

Continuous Variable:

A variable which can assume each and every value within a given range is called a continuous variable. It can occur in decimals.

For Example: Heights and Weights of students, Speed of a bus, the age of a Shopkeeper, the life time of a T.V etc…

Continuous Data:

Data which can be described by a continuous variable is called continuous data.
For Example: Weights of 50 students in a class.

Discrete Variable:

A variable which can assume only some specific values within a given range is called discrete variable. It cannot occur in decimals. It can occur in whole numbers.
For Example: Number of students in a class, number of flowers on the tree, number of houses in a street, number of chairs in a room etc…

Discrete Data:

Data which can be described by a discrete variable is called discrete data.
For Example: Number of students in a college.

Quantitative Variable:

A characteristic which varies only in magnitude from on individual to another is called quantitative variable. It can be measurable.
For Example: Wages, Prices, Heights, Weights etc…

Qualitative Variable:

A characteristic which varies only in quality from one individual to another is called qualitative variable. It cannot be measured.
For Example: Beauty, Marital Status, Rich, Poor, Smell etc…