Consider the profit of a manufacturing company in various years as given below
The profit for the year 1989 is not available .To estimate the profit for 1989 we use the technique called interpolation. Let x denote the year and y denote the profit. The independent variable x is called the argument and the dependent variable y is called the entry. If y is to be estimated for the value of x between two extreme points in a set of values, it is called interpolation.
There are two methods for interpolation. One is Graphical method and the other one is algebraic method.