Understand the Standard Deviation

Understand the Standard Deviation
Last Updated on 10/06/2024
Reading time: 2 minutes

Calculating the standard deviation helps you explain your AVERAGE calculation

  1. The AVERAGE

    The average is a very common Statistical calculation. It's a statistical measure that represents the central tendency of a set of values

  2. The Standard Deviation

    This calculation will highlight variations in the average

Analysing this situation

Let's say you have a classroom with 10 students

  • For the first exam, all the students had the same mark; 5
  • For the second exam, the result is totally different
    • 5 students have the mark 0
    • 5 students have the mark 10

The average is the same for both exams (5), but of course, the analysis can't be the same. This is where the standard deviation will help you to have a better analysis of your average results.

Same average but the analyze is different

Calculation of the standard deviation

  1. Write the function =STDEV
  2. Select your range of cells

=STDEV(B2:B11) => 0

=STDEV(C2:C11) => 5.27

Standard deviation calculation

What do these results mean?

  • 0 means that all values ​​in the series are equal to the average. There is no gap (or deviation) between the average and the values of the series.
  • On the other hand, for the second series, the result is very far from 0 and even exceeds the average value.

In other words, the standard deviation represents the dispersion of the data around the average. The more the result is close to 0, the more the data is centered on the average; 0 means no dispersion at all

Several formulas in Excel, why?

As you have certainly noticed, there are several functions in Excel that calculate the standard deviation.

All the function STDEV in Excel

In Excel 2010, Microsoft engineers asked significant statisticians to improve the speed of the calculations and their accuracy for large numbers of data.

  • The STDEV.P is based on the entire population (N). This function replaces the former STDEVP function.
  • The STDEV.S is based on a sample (N-1). This function replaces the former STDEV function.

The difference between the 2 calculation modes concerns the sample and, therefore, the divisor. If you calculate the standard deviation with the entire population, the divisor will equal N (with N, the number of elements). When you calculate for a sample, the divisor is N-1.

Tutorial video

Related Articles

1 Comment

  1. Jin John
    19/02/2021 @ 12:05

    This is very knowledgeable information for students, I gave you a favor in the form of an online calculator.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

Understand the Standard Deviation

Reading time: 2 minutes
Last Updated on 10/06/2024

Calculating the standard deviation helps you explain your AVERAGE calculation

  1. The AVERAGE

    The average is a very common Statistical calculation. It's a statistical measure that represents the central tendency of a set of values

  2. The Standard Deviation

    This calculation will highlight variations in the average

Analysing this situation

Let's say you have a classroom with 10 students

  • For the first exam, all the students had the same mark; 5
  • For the second exam, the result is totally different
    • 5 students have the mark 0
    • 5 students have the mark 10

The average is the same for both exams (5), but of course, the analysis can't be the same. This is where the standard deviation will help you to have a better analysis of your average results.

Same average but the analyze is different

Calculation of the standard deviation

  1. Write the function =STDEV
  2. Select your range of cells

=STDEV(B2:B11) => 0

=STDEV(C2:C11) => 5.27

Standard deviation calculation

What do these results mean?

  • 0 means that all values ​​in the series are equal to the average. There is no gap (or deviation) between the average and the values of the series.
  • On the other hand, for the second series, the result is very far from 0 and even exceeds the average value.

In other words, the standard deviation represents the dispersion of the data around the average. The more the result is close to 0, the more the data is centered on the average; 0 means no dispersion at all

Several formulas in Excel, why?

As you have certainly noticed, there are several functions in Excel that calculate the standard deviation.

All the function STDEV in Excel

In Excel 2010, Microsoft engineers asked significant statisticians to improve the speed of the calculations and their accuracy for large numbers of data.

  • The STDEV.P is based on the entire population (N). This function replaces the former STDEVP function.
  • The STDEV.S is based on a sample (N-1). This function replaces the former STDEV function.

The difference between the 2 calculation modes concerns the sample and, therefore, the divisor. If you calculate the standard deviation with the entire population, the divisor will equal N (with N, the number of elements). When you calculate for a sample, the divisor is N-1.

Tutorial video

Related Articles

1 Comment

  1. Jin John
    19/02/2021 @ 12:05

    This is very knowledgeable information for students, I gave you a favor in the form of an online calculator.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *