Statistics & Sequences

This subcategory contains 7 tools for analysing series and counting possibilities. Standard Deviation, Geometric Mean and Arithmetic sequence illustrate the uses. Fibonacci sequence, Combinations, Permutations and Percentage change complete the page. They are free and need no account, useful for statistics, probability, progressions and numeric changes.

Choose based on your starting data. Standard Deviation computes population mean, variance and standard deviation, Geometric Mean works with positive values and Percentage change measures a shift between two values. For progressions, Arithmetic sequence and Fibonacci sequence each follow their own logic. To count choices, Combinations and Permutations give exact numbers. Start with the result you need: spread, mean, term, sum or number of possibilities.

How to use

  1. Define the expected result: spread, mean, term in a sequence, sum, counting or percentage change.
  2. To analyse a series, start with Standard Deviation, then use Geometric Mean if all values are positive.
  3. For a progression, choose Arithmetic sequence or Fibonacci sequence depending on the rule, and check the requested rank before reading the term.
  4. To count possibilities, use Combinations or Permutations depending on whether order matters. For a change, finish with Percentage change.

Frequently asked questions

What is the difference between Combinations and Permutations?

Combinations counts ways to choose k from n without order, while Permutations counts arrangements where order matters. Both return an exact number of possibilities for the stated case.

Does Standard Deviation use the whole population?

Its description refers to the population mean, variance and standard deviation. It therefore treats all the values you provide as the population being analysed.

Does Arithmetic sequence also calculate a sum?

Yes, it calculates a term and the sum of the first n terms. For multiplicative growth, look at Fibonacci sequence or Percentage change depending on your need.

Does Geometric Mean accept negative values?

No, its description refers to positive values. For a series containing negative numbers or a zero, use Standard Deviation for spread instead, or check whether the geometric mean is appropriate.

Is Percentage change used to compare two periods?

Yes, it computes the change between two values. This helps measure a rise or fall between two moments. For a regular progression, also look at Arithmetic sequence and Fibonacci sequence.

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