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You can use one of the following methods to plot a line of best fit in R:

**Method 1: Plot Line of Best Fit in Base R**

#create scatter plot of x vs. y plot(x, y) #add line of best fit to scatter plot abline(lm(y ~ x))

**Method 2: Plot Line of Best Fit in ggplot2**

library(ggplot2) #create scatter plot with line of best fit ggplot(df, aes(x=x, y=y)) + geom_point() + geom_smooth(method=lm, se=FALSE)

The following examples show how to use each method in practice.

**Example 1: Plot Line of Best Fit in Base R**

The following code shows how to plot a line of best fit for a simple linear regression model using base R:

#define data x #create scatter plot of x vs. y plot(x, y) #add line of best fit to scatter plot abline(lm(y ~ x))

Feel free to modify the style of the points and the line as well:

#define data x #create scatter plot of x vs. y plot(x, y, pch=16, col='red', cex=1.2) #add line of best fit to scatter plot abline(lm(y ~ x), col='blue' , lty='dashed')

We can also use the following code to quickly calculate the line of best fit:

#find regression model coefficients summary(lm(y ~ x))$coefficients Estimate Std. Error t value Pr(>|t|) (Intercept) -0.8928571 1.0047365 -0.888648 4.084029e-01 x 2.3095238 0.1989675 11.607544 2.461303e-05

The line of best fit turns out to be: **y = -0.89 + 2.32x**.

**Example 2: Plot Line of Best Fit in ggplot2**

The following code shows how to plot a line of best fit for a simple linear regression model using the ggplot2 data visualization package:

library(ggplot2) #define data df frame(x=c(1, 2, 3, 4, 5, 6, 7, 8), y=c(2, 5, 6, 7, 9, 12, 16, 19)) #create scatter plot with line of best fit ggplot(df, aes(x=x, y=y)) + geom_point() + geom_smooth(method=lm, se=FALSE)

Feel free to modify the aesthetics of the plot as well:

library(ggplot2) #define data df frame(x=c(1, 2, 3, 4, 5, 6, 7, 8), y=c(2, 5, 6, 7, 9, 12, 16, 19)) #create scatter plot with line of best fit ggplot(df, aes(x=x, y=y)) + geom_point(col='red', size=2) + geom_smooth(method=lm, se=FALSE, col='purple', linetype='dashed') + theme_bw()

**Additional Resources**

The following tutorials explain how to perform other common operations in R:

How to Perform Simple Linear Regression in R

How to Perform Multiple Linear Regression in R

How to Interpret Regression Output in R