- Trending Categories
- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies

- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who

# How to find mean and standard deviation from frequency table in R?

To find the mean and standard deviation from frequency table, we would need to apply the formula for mean and standard deviation for frequency data. For example, if we have a data frame called df that contains a column x for units and frequency for counts then the mean and standard deviation can be calculated as −

Mean = sum(df$x*df$frequency)/sum(df$frequency) SD = sqrt(sum((df$x−Mean)**2*df$frequency)/(sum(df$frequency)−1)) respectively.

## Example1

x<−rpois(20,5) frequency<−sample(1:100,20) df1<−data.frame(x,frequency) df1

## Output

x frequency 1 6 4 2 7 26 3 1 86 4 2 6 5 4 52 6 4 61 7 1 55 8 4 23 9 8 38 10 3 40 11 8 54 12 10 56 13 7 74 14 9 70 15 7 59 16 16 95 17 4 20 18 5 9 19 4 82 20 9 45

## Example

Mean=sum(df1$x*df1$frequency)/sum(df1$frequency) Mean

## Output

[1] 6.55288

## Example

SD=sqrt(sum((df1$x−Mean)**2*df1$frequency)/(sum(df1$frequency)−1)) SD

## Output

[1] 4.172396

## Example2

y<−rnorm(20,25,3.24) frequency<−rpois(20,10) df2<−data.frame(y,frequency) df2

## Output

y frequency 1 27.44960 7 2 25.80343 5 3 22.64088 8 4 22.39061 7 5 24.55087 7 6 24.41826 16 7 23.24647 11 8 25.61511 9 9 22.42244 11 10 26.77522 14 11 21.89209 11 12 22.95852 8 13 25.79808 16 14 22.39654 6 15 21.20728 12 16 28.25911 17 17 26.67983 8 18 25.24964 12 19 20.92070 8 20 28.25806 7

## Example

Mean=sum(df2$y*df2$frequency)/sum(df2$frequency) Mean

## Output

[1] 24.58724

## Example

SD=sqrt(sum((df2$y−Mean)**2*df2$frequency)/(sum(df2$frequency)−1)) SD

## Output

[1] 2.284964

- Related Articles
- How to create boxplot using mean and standard deviation in R?
- Plot mean and standard deviation in Matplotlib
- How to create a line chart with mean and standard deviation using ggplot2 in R?
- How to find the moving standard deviation in an R matrix?
- PyTorch – How to normalize an image with mean and standard deviation?
- How to find the moving standard deviation in an R data frame?
- How to compute the mean and standard deviation of a tensor in PyTorch?
- How to find the standard error of mean in R?
- How to find the standard deviation for rows in an R data frame?
- How to find the row standard deviation of columns having same name in R matrix?
- Generate random numbers by giving certain mean and standard deviation in Excel
- How to divide the matrix rows by row standard deviation in R?
- How to find the column standard deviation if some columns are categorical in R data frame?
- How to find the row standard deviation of columns having same name in R data frame?
- How to calculate standard deviation in Excel?

Advertisements