In this article, we are going to find the standard deviation of a column in a dataframe in R Programming Language.

To select the desired column of a dataframe **$** is used.

**Syntax:**

dataframe$column_name

**Formula for variance:**

where n is the total number of observations and x bar is the mean

**Formula for standard deviation:**

In the R programming language, for finding standard deviation on set of data, the method used is **sd()**

**Syntax**:

sd(data_values)

Where data-values are a vector input or data frame input.

Given below are some examples to help you understand this better

**Example 1:**

## R

`# data1 with vector of elements` `data1=` `c` `(1,2,3,4,5)` ` ` `# data2 with vector of elements` `data2=` `c` `(` `"sravan"` `,` `'bobby'` `,` `'rohith'` `,` `'gnanu'` `,` `'ojaswi'` `)` ` ` `# give input to the data which is a dataframe` `data=` `data.frame` `(a1=data1,a2=data2)` ` ` `# finding standard deviation of dataframe` `# column 1` `print` `(` `sd` `(data$a1))` |

**Output:**

[1] 1.581139

**Example 2:**

## R

`# data1 with vector of elements` `data1=` `c` `(1,2,3,4,5)` ` ` `# data2 with vector of elements` `data2=` `c` `(10,20,30,40,50)` ` ` `# give input to the data which is a` `# dataframe` `data=` `data.frame` `(a1=data1,a2=data2)` ` ` `# finding standard deviation of dataframe` `# column 1` `print` `(` `sd` `(data$a1))` ` ` `# finding standard deviation of dataframe` `# column 2` `print` `(` `sd` `(data$a2))` |

**Output:**

[1] 1.581139

[1] 15.81139

**Example 3:**

## R

`# data1 with vector of elements (float` `# values)` `data1=` `c` `(1.0,2,3,4,5,8)` ` ` `# data2 with vector of elements(float` `# values)` `data2=` `c` `(10,20.5,30.3,40,50,67.89)` ` ` `# give input to the data which is a ` `# dataframe` `data=` `data.frame` `(a1=data1,a2=data2)` ` ` `# finding standard deviation of dataframe ` `# column 1` `print` `(` `sd` `(data$a1))` ` ` `# finding standard deviation of dataframe ` `# column 2` `print` `(` `sd` `(data$a2))` |

**Output:**

[1] 2.483277

[1] 20.86387