# How to extrapolate data from a table

**Extrapolation **is a statistical technique used to estimate values that are beyond the range of a given set of data. It is commonly used in finance, engineering, and other fields to predict trends and make informed decisions. In this blog post, we will explore how to **Extrapolate** data from a table in Excel.

Here we have a dataset that contains two columns: **Years **and** Sales. **In the dataset from year **2015 **to **2019 **sales values are unknown, we will be using the **Extrapolation** technique to predict the sales from year **2015 **to **2019**. Let’s have a look at the dataset first.

## Method – 1 Using the formula for Extrapolation.

The generic form of linear interpolation formula used to estimate a value between two known data points is:

y = y1 + (x – x1) * ((y2 – y1) / (x2 – x1))

where:

x1 and y1 are the x and y values of the first data point

x2 and y2 are the x and y values of the second data point

x is the x value for which you want to estimate a corresponding y value

y is the estimated y value for x

## Step – 1 Type the formula.

- Select the cell where you want to show the result.
- The formula we used for extrapolation is:

**=B5+(A7-A5)/(A6-A5)*(B6-B5)**

- Formula breakdown:

**B5** and **B6** are the known values in the **y-axis** (dependent variable)

**A5** and **A6** are the known values in the **x-axis** (independent variable)

**A7** is the value in the **x-axis** at which you want to predict the corresponding value in the **y-axis.**

## Step – 2 Find the rest of the values.

- Select the cell where you typed the formula.
- Click on the bottom right of the cell and drag it to the rest of the cells as shown above.

## Method – 2 TREND formula for Extrapolation.

## Step – 1 Type the formula.

- Select the cell where you want to type the formula.
- Then type the formula:

**=TREND(B2:B6, A2:A6, A7)**

- Formula breakdown:

**=TREND(known_y’s, known_x’s, new_x’s)**

**known_y’s: **This is the range of dependent variables (y-values) for which you have data.

**known_x’s: **This is the range of independent variables (x-values) for which you have data.

**new_x’s: **This is the range of independent variables (x-values) for which you want to predict new y-values.

## Step – 2 Find the rest of the values.

- Select the cell where you typed the formula.
- Click on the bottom right of the cell and drag it to the rest of the cells as shown above.

## Method – 3 Forecast formula for Extrapolation.

## Step – 1 Type the formula.

- Select the cell where you want to type the formula.

**FORECAST(A7,B2:B6,A2:A6)**

- Formula Breakdown:

**=FORECAST(x,known_y’s,known_x’s)**

**x: **This is the x-value for which you want to predict a new y-value.

**known_y’s: **This is the range of dependent variables (y-values) for which you have data.

**known_x’s: **This is the range of independent variables (x-values) for which you have data.

## Step – 2 Find the rest of the values.

- Select the cell with the formula.
- Click on the bottom right of the cell and drag it to the rest of the cells as shown above.

## Method – 4 Graph for Extrapolation.

## Step – 1 Select the Table.

- Select the dataset.
- Go to the
**Insert**tab. - In the
**Charts**group click on**Recommended****Charts.**

## Step – 2 Insert The Graph.

- After clicking on the
**Recommended Chart**., click on the appropriate graph. - After the graph has been added, click on it.
- Then click on the plus sign, and it will show the
**Chart Elements.** - Check the checkbox of
**Trendline.** - Then the graph will show the prediction of sales from 2015 to 2019.