The standard deviation formula for grouped data is: σ² = Σ(Fi * Mi2) - (n * μ2) / (n - 1) , where σ² is the variance. To obtain the standard deviation, take the square root of the variance.
What is the formula to calculate standard deviation?
To calculate the standard deviation of those numbers:
- Work out the Mean (the simple average of the numbers)
- Then for each number: subtract the Mean and square the result.
- Then work out the mean of those squared differences.
- Take the square root of that and we are done!
What is the formula of grouped data?
To calculate the mean of grouped data, the first step is to determine the midpoint of each interval or class. These midpoints must then be multiplied by the frequencies of the corresponding classes. The sum of the products divided by the total number of values will be the value of the mean.
