## Method 1 – Adding Trendline Equation in Excel

**Steps:**

- Select the chart in which you want to add the trendline.
- Go to
**Chart Elements**. - Select
**Trendline**.

You will see a **trendline **has been added to your chart.

Change the color of the **trendline** to make it more visible.

- Right-click on the
**trendline**. - Select
**Format Trendline**.

See that the **Format Timeline **option will appear on the right side of the screen.

- Go to
**Fill & Line**. - Select
**Color**.

See a list of colors that will appear.

- Select the color you want. Here, I selected
**Red**.

See that you have got your desired **trendline**.

Change the **trendline** type.

- Right-click on the trendline.
- Select
**Format Trendline**.

The **Format Timeline **option will appear on the right side of the screen.

- Go to the
**Trendline Options**. - Select the
**trendline**type you want. We kept it**linear**, which is the default option, but you can select any other option.

Add the **trendline equation**.

- Right-click on the trendline.
- Select
**Format Trendline**.

The **Format Timeline **option will appear on the right side of the screen.

- Go to the
**Trendline Options**. - Select
**Display Equation on chart**.

See the **trendline equation **on the chart.

## Method 2 – Using Trendline Equation in Excel to Forecast Data

**Steps:**

- Select the cell where you want to forecast the data. We selected cell
**C10**. - In cell
**C10**write the following formula.

`=0.114*B10-2.8`

We used the trendline equation from the chart. I took **B10 **as **X**. The formula will return the **Y **value.

- Press
**ENTER**to get the**Y.**

- Drag the
**Fill Handle**to copy the formula.

See that you have got your forecasted data using the** trendline equation** in Excel.

## Method 3 – Using Trendline Equation in Excel to Get Values for Any Given X

**Steps:**

- Select the cell where you want to get the
**Y**value for a given**X**. We selected cell**C12**. - In cell
**C12**write the following formula.

`=0.114*B12-0.8`

We used the **trendline equation** from the chart. We took **B12 **as **X**. Now, the formula will return the **Y **value.

- Press
**ENTER**to get the**Y.**

- Drag the
**Fill Handle**to copy the formula.

See that you have your **Y **values for any given **X **using the** trendline equation** in Excel.

## Method 4 – Inserting Linear Trendline Equation to Find Slope and Intercept

**Steps:**

- Select the cell where you want to calculate the
**Slope**. We selected cell**G5**. - In cell
**G5**write the following formula.

`=SLOPE(C5:C9,B5:B9)`

In the **SLOPE ** function, I selected **C5:C9 **as **known_ys **and **B5:B9 **as **known_xs**. This function will return the value of the **Slope **for the dataset.

- Press
**ENTER**to get the value of the**Slope**.

Calculate the **Intercept**.

- Select the cell where you want to calculate the
**Intercept**. We selected cell**G6**. - In cell
**G6**write the following formula.

`=INTERCEPT(C5:C9,B5:B9)`

In the **INTERCEPT** function, I selected **C5:C9 **as **known_ys **and **B5:B9 **as **known_xs**. This function will return the value of the **Intercept **for the dataset.

- Press
**ENTER**to get the value of the**Intercept**.

See that the Slope and Intercept values from the equation match the values we got using functions. This means the values from the** trendline equation** are correct.

## Method 5 – Using Exponential Trendline Equation in Excel to Find the Coefficients

**Steps:**

- Select the cell where you want to calculate the
**Coefficient a**. We selected cell**G5**. - In cell
**G5**write the following formula.

`=EXP(INDEX(LINEST(LN(C5:C9),B5:B9),1,2))`

**Formula Breakdown**

- Here, in the
**EXP**function, used the**INDEX**function as a**number**that will return the value from a range. - Now, in the
**INDEX**function, used the**LINEST**function as array 1 as**row_num**, and**2**as**column_num**. - Next, In
**the LINEST function**, selected**LN(C5:C9)**as**known_ys**the**LN**function will return the natural logarithm of the given range, and**B5:B9**as**known_xs**. - Finally, the
**EXP**function will return the result of the constant**e**raised to the power of the**number,**which will be our**coefficient a**.

- Press
**ENTER**to get the**coefficient a**.

Calculate **Coefficient b**.

- Select the cell where you want to calculate the
**Coefficient b**. We selected cell**G6**. - In cell
**G6**write the following formula.

`=INDEX(LINEST(LN(C5:C9),B5:B9),1)`

**Formula Breakdown**

- In the
**INDEX**function, I used a**LINEST**function as**array**and**1**as**row_num**. - In the
**LINEST**function, I selected**LN(C5:C9)**as**known_ys**which will return the natural logarithm of the given range, and**B5:B9**as**known_xs**. - The
**INDEX**function will return the value from the**table**which will be**Coefficient b**.

- Press
**ENTER**to get the**Coefficient b**.

See that the values of **Coefficient a **and **Coefficient b **from the equation match the values we got using functions. This means the values from the** trendline equation** are correct.

## Method 6 – Applying Logarithmic Trendline Equation in Excel

**Steps:**

- Select the cell where you want to calculate the
**Constant a**. We selected cell**G5**. - In cell
**G5**write the following formula.

`=INDEX(LINEST(C5:C9,LN(B5:B9)),1)`

**Formula Breakdown**

- In the
**INDEX**function, used a**LINEST**function as**array**and**1**as**row_num**. - In the
**LINEST**function, selected**C5:C9**as**known_ys**, and**LN(B5:B9)**as**known_xs**which will return the natural logarithm of the given range. - The
**INDEX**function will return the value from the**table**will be**Constant a**.

- Press
**ENTER**to get the**Constant a**.

Calculate **Constant b**.

- Select the cell where you want to calculate the
**Constant b**. Here, I selected cell**G6**. - In cell
**G6**write the following formula.

`=INDEX(LINEST(C5:C9,LN(B5:B9)),1,2)`

**Formula Breakdown**

- In the
**INDEX**function, used a**LINEST**function as**array**and**1**as**row_num**and**2**as**column_num**. - In the
**LINEST**function, selected**C5:C9**as**known_ys**, and**LN(B5:B9)**as**known_xs**will return the natural logarithm of the given range. - The
**INDEX**function will return the value from the**table**will be**Constant b**.

- Press
**ENTER**to get the**Constant b**.

See that the values of **Constant a **and **Constant b **from the equation match the values we got using functions. This means the values from the** trendline equation** are correct.

## Method 7 – Using Polynomial Trendline Equation in Excel

**Steps:**

- Select the cell where you want to calculate the
**Coefficient b1**. We selected cell**G5**. - In cell
**G5**write the following formula.

`=INDEX(LINEST(C5:C9,B5:B9^{1,2}),1)`

**Formula Breakdown**

- In the
**INDEX**function, I used a**LINEST**function as**array**and**1**as**row_num**. - In the
**LINEST**function, I selected**C5:C9**as**known_ys**, and**B5:B9^{1,2}**as**known_xs**which will raise the range**B5:B9**to the**power**of**{1,2}**. - The
**INDEX**function will return the value from the**table**will be**Coefficient b1**.

- Press
**ENTER**to get**Coefficient b1**.

Calculate **Coefficient b2**.

- Select the cell where you want to calculate the
**Coefficient b2**. Here, I selected cell**G6**. - In cell
**G6**write the following formula.

`=INDEX(LINEST(C5:C9,B5:B9^{1,2}),1,2)`

**Formula Breakdown**

- In the
**INDEX**function, used a**LINEST**function as**array**,**1**as**row_num**and,**2**as**column_num**. - In the
**LINEST**function, selected**C5:C9**as**known_ys**, and**B5:B9^{1,2}**as**known_xs**which will raise the range**B5:B9**to the**power**of**{1,2}**. - The
**INDEX**function will return the value from the**table**will be**Coefficient b2**.

- Press
**ENTER**to get**Coefficient b2**.

Calculate **Constant a**.

- Select the cell where you want to calculate the
**Constant a**. We selected cell**G7**. - In cell
**G7**write the following formula.

`=INDEX(LINEST(C5:C9,B5:B9^{1,2}),1,3)`

**Formula Breakdown**

- In the
**INDEX**function, used a**LINEST**function as**array**,**1**as**row_num**and,**3**as**column_num**. - In the
**LINEST**function, selected**C5:C9**as**known_ys**, and**B5:B9^{1,2}**as**known_xs**which will raise the range**B5:B9**to the**power**of**{1,2}**. - The
**INDEX**function will return the value from the**table**which will be**Constant a**.

- Press
**ENTER**to get**Constant a**.

See that the values of **Coefficient b1**, **Coefficient b2**, and **Constant a **from the equation match the values that we got using functions. This means the values from the** trendline equation** are correct.

## Method 8 – Using Power Trendline Equation in Excel

**Steps:**

- Select the cell where you want to calculate the
**Constant a**. We selected cell**G5**. - In cell
**G5**write the following formula.

`=EXP(INDEX(LINEST(LN(C5:C9),LN(B5:B9), ,),1,2))`

**Formula Breakdown**

- In the
**EXP**function, used an**INDEX**function as a**number**that will return the value from a range. - In the
**INDEX**function, used a**LINEST**function as an**array**and**1**as**row_num**, and**2**as**column_num**. - In the
**LINEST**function, selected**LN(C5:C9)**as**known_ys**which will return the natural logarithm of the given range, and**LN(B5:B9)**as**known_xs**which will return the natural logarithm of the given range, and left**const**and**stats** - The
**EXP**function will return the result of the constant**e**raised to the power of the**number**which will be our**Constant a**.

- Press
**ENTER**to get the**Constant a**.

Now, I will calculate **Constant b**.

- Select the cell where you want to calculate the
**Constant a**. We selected cell**G6**. - In cell
**G6**write the following formula.

`=INDEX(LINEST(LN(C5:C9),LN(B5:B9),,),1)`

**Formula Breakdown**

- In the
**INDEX**function, used a**LINEST**function as an**array**and**1**as**row_num**. - In the
**LINEST**function, selected**LN(C5:C9)**as**known_ys**which will return the natural logarithm of the given range, and**LN(B5:B9)**as**known_xs**which will also return the natural logarithm of the given range, and left**const**and**stats** - The
**INDEX**function will return the value from the**table**which will be**Constant b**.

- Press
**ENTER**to get the**Constant b**.

See that the values of **Constant a **and **Constant b **from the equation match the values that we got using functions. This means the values from the** trendline equation** are correct.

**Download Practice workbook**

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