Statistics

Chi-Square Independence Calculator

Analyze an observed contingency table with expected counts, chi-square, degrees of freedom and an approximate p-value.

Chi-Square Independence Calculator

Resultp = 0.003873388838

Model and interpretation

Use an at-least 2×2 table of nonnegative integer counts from independent observations. Empty row or column totals are invalid. This chi-square reference approximation is intended for expected counts of at least 5 in every cell; smaller expectations trigger a warning. It is not Fisher's exact test or proof of causation. 2 ≤ r,c ≤ 20; N ≤ 10⁹.

χ²
19.178
df
6
p
0.00387339
N
309
#(E < 5)
0
#(E < 1)
0
Data table (12)
ijOᵢⱼEᵢⱼ
111522.5113
122120.9903
134538.9385
141311.5599
212622.9903
223121.4369
233439.767
24511.8058
313328.4984
321726.5728
334949.2945
342014.6343

What this calculator answers

Chi-Square Independence Calculator applies the registered method “Eᵢⱼ = rowᵢ × columnⱼ / N; χ² = Σ(Oᵢⱼ−Eᵢⱼ)²/Eᵢⱼ; df = (r−1)(c−1)” to the displayed Observed counts (one table row per line) inputs. Both worked examples come from the production calculation engine, and NIST/SEMATECH — Contingency tables defines the cited method or convention; no hidden inputs or current external data are inferred.

Variables, defaults, and limits

Observed counts (one table row per line)
Observed counts (one table row per line) is a structured text input. The displayed starter value is 15; 21; 45; 13 26; 31; 34; 5 33; 17; 49; 20; it is an example, not a hidden assumption.
Default: 15; 21; 45; 13 26; 31; 34; 5 33; 17; 49; 20
Accepted values: The field has no narrower HTML limit, but it must still satisfy the documented formula domain and produce a finite result.

Formula and calculation rule

R[chi-square-calculator]=Eᵢⱼ = rowᵢ × columnⱼ / N; χ² = Σ(Oᵢⱼ−Eᵢⱼ)²/Eᵢⱼ; df = (r−1)(c−1); x₁=Observed counts (one table row per line)

Chi-Square Independence Calculator evaluates the registered expression “R[chi-square-calculator]=Eᵢⱼ = rowᵢ × columnⱼ / N; χ² = Σ(Oᵢⱼ−Eᵢⱼ)²/Eᵢⱼ; df = (r−1)(c−1); x₁=Observed counts (one table row per line)” with the validated inputs. Full calculation precision is retained until the result is formatted for display.

Worked examples

Chi-Square Independence Calculator evaluated example 1

Use the page’s labelled starter inputs to verify Chi-Square Independence Calculator.

Inputs
  • Observed counts (one table row per line): 15; 21; 45; 13 26; 31; 34; 5 33; 17; 49; 20

Evaluated result: p = 0.003873388838

Chi-Square Independence Calculator evaluated example 2

Change one valid input or choice and evaluate Chi-Square Independence Calculator again to check that the result responds deterministically.

Inputs
  • Observed counts (one table row per line): 10; 20 20; 10

Evaluated result: p = 0.009823274508

Assumptions

  • Chi-Square Independence Calculator uses the visitor-entered values exactly as labelled; it does not retrieve private records or current rates.
  • The calculation is limited to the declared relationship: R[chi-square-calculator]=Eᵢⱼ = rowᵢ × columnⱼ / N; χ² = Σ(Oᵢⱼ−Eᵢⱼ)²/Eᵢⱼ; df = (r−1)(c−1); x₁=Observed counts (one table row per line).
  • Intermediate values are not rounded; display rounding is applied only at the presentation boundary.
  • The deterministic calculation runs locally and does not upload calculator inputs to the application API.
  • The result is an educational arithmetic result and excludes facts that are not represented by an input.

Validation and boundaries

  • Every visible required input must be present; a missing value is never replaced with zero.
  • NaN, positive or negative infinity, unsafe overflow, and a non-finite final result are rejected.
  • Field-specific minimums, maximums, and choices apply to Observed counts (one table row per line).
  • Zero, negative values, and discrete counts are accepted only when the displayed field definition permits them.

Review and correction links

Common mistakes

  • Confirm the meaning and unit of Observed counts (one table row per line) before calculating; a numerically valid value can still use the wrong convention.
  • Do not round intermediate values when checking the result, because early rounding can change the last displayed digits.
  • Changing an unstated real-world assumption does not change the calculator until the corresponding displayed input is changed.
  • Use the result as the answer to the displayed mathematical question, not to a different word problem with hidden conditions.

Frequently asked questions

What question does Chi-Square Independence Calculator answer?
Analyze an observed contingency table with expected counts, chi-square, degrees of freedom and an approximate p-value. The implemented relationship is R[chi-square-calculator]=Eᵢⱼ = rowᵢ × columnⱼ / N; χ² = Σ(Oᵢⱼ−Eᵢⱼ)²/Eᵢⱼ; df = (r−1)(c−1); x₁=Observed counts (one table row per line).
Which inputs does Chi-Square Independence Calculator use?
It uses the visible fields Observed counts (one table row per line). No hidden value is substituted for an omitted required input.
What happens when Chi-Square Independence Calculator receives an invalid or extreme value?
The page rejects missing, ambiguous, out-of-range, or non-finite values and refuses to display a non-finite result.
Why can Chi-Square Independence Calculator differ from another result?
Different unit conventions, endpoint policies, fee or rate assumptions, formula domains, and premature rounding can produce a different answer.
Can I use Chi-Square Independence Calculator as professional advice?
No. It answers the displayed mathematical question and cannot account for omitted real-world facts.
How can I verify the Chi-Square Independence Calculator result?
Recalculate the two evaluated examples without rounding intermediate values and compare the declared formula or convention with NIST/SEMATECH — Contingency tables.

Source and review scope

NIST/SEMATECH — Contingency tables

Scope: NIST/SEMATECH — Contingency tables is used to check the formula, definition, or convention relevant to Chi-Square Independence Calculator. The citation does not supply current personal, lender, tax, medical, or market data.

Source checked:

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To report a possible formula, translation, source, or example error in Chi-Square Independence Calculator, email support@calculatortoolset.com with the page URL, inputs, observed result, and independently expected result.

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