# How to Use Method of Least Squares in Google Sheets

The method of least squares is a method we can use to find the regression line that best fits a given dataset.

The following video provides a brief explanation of this method:

To use the method of least squares to fit a regression line in Google Sheets, we can use the LINEST() function.

The following step-by-step example shows how to use this function in practice.

## Step 1: Enter the Data

First, let’s create the following dataset in Google Sheets:

## Step 2: Use Method of Least Squares to Fit Regression Line

We can use the =LINEST(known_ys, known_xs) function to use the method of least squares to fit a regression line to this dataset.

To do so, type the following formula into cell D1:

```=LINEST(B2:B16, A2:A16)
```

The following screenshot shows how to use this formula in practice:

The coefficients of the regression line are shown in cells D1 and D2.

## Step 3: Interpret the Results

Using the coefficients from the =LINEST() function, we can write the following fitted regression line:

y = 11.55211 + 1.07949(x)

We can use this equation to estimate the value of y based on the value of x.

For example, if x = 10 then we would estimate that y would be equal to 22.347:

y = 11.55211 + 1.07949(10) = 22.347

## Step 4: Plot the Results

Lastly, we can plot the dataset along with the fitted regression line.

To do so, highlight the cell range A2:B16, then click the Insert tab along the top ribbon, then click Chart.

In the Chart editor panel, choose Scatter chart as the chart type:

Then click the Customize tab in the Chart editor, then click the dropdown arrow next to Series, then scroll down and check the box next to Trendline:

The fitted regression line will appear on the scatter plot:

The individual points in the plot represent the (x,y) pairs from the original dataset and the straight line through the data points represents the fitted regression line.