The **mean()** function is used to calculate mean value of numeric vector,dataframe or list in R.

The following method shows how you can do it with syntax.

**Method: Use mean() Function**

```
mean(x)
```

The following examples show how to use **mean()** function in R.

## Use mean() Function to Calculate Mean of Vector

Let’s see how we can calculate mean of numeric vector using **mean()** function:

```
# Declare vector
x <- c(2.39,11.25,12.15,13.48,13.78,12.89,12.21,12.58)
# Calculate mean of vector
mean_x = mean(x)
# Show mean
print(mean_x)
```

Output:

```
[1] 11.34125
```

As output shows the mean of vector *x* is 11.34125.

## Use mean() Function to Calculate Mean of Data Frame Column

Suppose we want to calculate mean of one the column of data frame using **mean()** function:

```
# Create data frame
df <- data.frame(Machine_name=c("A","B","C","D","E","F"),
Pressure=c(78.2, 71.7, 80.21, 83.12, 82.56, 79.50),
Temperature=c(31, 35, 36, 36, 38, 32),
Status=c(TRUE,TRUE,FALSE,FALSE,FALSE,TRUE))
# Find mean value for column of data frame
m = mean(df$Pressure)
# Print mean value
print(m)
```

Output:

```
[1] 79.215
```

The **mean()** function calculate the mean of *Pressure* column of data frame which is *79.215*.