# What is the use of the best fit line?

The best fit line is also called a regression line.

## Answer: The best fit line helps us to predict future values.

The line of best fit is a line that best represents the relationship between a scatter plot of data points.

**Explanation:**

Various types of best fit line are-

- Linear Best Fit Line: The line of best fit is a straight line when data points appear to be in a straight line.
- Polynomial Best Fit Line: A polynomial best fit line has many curves and bumps. In the real world, data usually follows a polynomial trend.
- Exponential Best Fit Line: An exponential best fit line shows exponential growth. Example: rise in COVID-19 cases etc.

The least-square method is a more accurate way of finding the line of best fit. Use the following steps to find out the equation of the best fit line for a set of data points (x1,y1),(x2,y2)...(xn,yn).

First, calculate the mean values of x and y.

Then, with the help of these values calculate slope of the line m = (Σ (xi - X) (yi - Y)) / (xi - X)^{2}

The best fit line equation will be b = Y - mX.

Therefore, the best fit line is used to predict future values.