Authoritative Data Source and Methodology
Primary references:
- NIST/SEMATECH e-Handbook of Statistical Methods (2012), National Institute of Standards and Technology. See Descriptive Statistics chapters. URL: https://www.itl.nist.gov/div898/handbook/
- OpenStax, Introductory Statistics, current edition. URL: https://openstax.org/details/books/introductory-statistics
Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.
The Formulas Explained
Mean (arithmetic average):
\\[
\\bar{x} = \\frac{1}{n}\\sum_{i=1}^{n} x_i
\\]
Median (middle value in ordered data):
For odd n:
\\[
\\tilde{x} = x_{\\left(\\frac{n+1}{2}\\right)}
\\]
For even n:
\\[
\\tilde{x} = \\frac{x_{\\left(\\frac{n}{2}\\right)} + x_{\\left(\\frac{n}{2}+1\\right)}}{2}
\\]
Mode (most frequent value(s)):
\\[
\\operatorname*{Mode} = \\operatorname*{arg\\,max}_v f(v)
\\]
Range:
\\[
R = \\max(x) - \\min(x)
\\]
Glossary of Inputs and Results
How It Works: A Step-by-Step Example
Suppose you enter the dataset: 2, 3, 5, 5, 6, 7, 8.
- Sort the data (ascending): 2, 3, 5, 5, 6, 7, 8.
- Count: n = 7; Sum = 2 + 3 + 5 + 5 + 6 + 7 + 8 = 36.
- Mean: \\( \\bar{x} = 36/7 \\approx 5.142857 \\) → 5.14 (2 decimals).
- Median: n is odd, middle value is the 4th item → 5.
- Mode: value with highest frequency → 5 (appears twice).
- Range: max − min = 8 − 2 = 6.
Frequently Asked Questions (FAQ)
FAQ list
1) Which separators can I use for input data?
Commas, spaces, tabs, and new lines are supported. The tool auto-detects them.
2) How are multiple modes handled?
If multiple values share the highest frequency, the calculator reports each of them (multimodal).
3) What happens to text mixed with numbers?
By default, stray text tokens are ignored. The “Notes” area will list anything skipped so you can correct it if needed.
4) How many decimal places are supported?
You can select from 0 to 8 decimal places. Results use standard rounding to the chosen precision.
5) Does sorting affect the calculations?
Sorting only affects how values are displayed. It does not change the computed statistics.
6) Can I copy the results?
Yes. Use the “Copy results” button to copy a clean, plain-text summary to your clipboard.
7) Is this calculator based on authoritative sources?
Yes. Definitions and formulas align with the NIST/SEMATECH e-Handbook of Statistical Methods and OpenStax Introductory Statistics.