For the complete documentation index, see llms.txt.
Compare two variances with an F test, or turn an F statistic into a p-value and critical values.
One POST adds F-Test / F-Distribution Calculator to your app, site, workflow, or agent — formula, validation, edge cases, and docs already handled.
prefer a UI? Open the F-Test / F-Distribution Calculator on miniwebtool.com →
POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run
| Field | Type | Req. |
|---|---|---|
mode
variances | samples | statistic
|
str |
— |
sd_1
sample 1 standard deviation (variances mode)
|
float |
— |
sd_2
sample 2 standard deviation (variances mode)
|
float |
— |
n_1
sample 1 size (variances mode)
|
int |
— |
n_2
sample 2 size (variances mode)
|
int |
— |
sample_1
comma-separated data (samples mode)
|
str |
— |
sample_2
comma-separated data (samples mode)
|
str |
— |
f_value
F statistic (statistic mode)
|
float |
— |
df_1
numerator degrees of freedom (statistic mode)
|
int |
— |
df_2
denominator degrees of freedom (statistic mode)
|
int |
— |
alpha
significance level
|
float |
— |
tail
two | right
|
str |
— |
65536 bytes.hash_only{
"request_id": "01K...",
"tool": "f-test-f-distribution-calculator",
"tool_version": "2026-04-22",
"credits_used": 1,
"result": { ... }
}
1,000 free calls/mo · no card · key arrives by email
curl -X POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run \
-H 'Authorization: Bearer mwt_live_YOUR_KEY' \
-H 'Content-Type: application/json' \
-d '{"mode":"variances","sd_1":12.5,"sd_2":8.4,"n_1":25,"n_2":20,"alpha":0.05,"tail":"two"}'
import requests
resp = requests.post(
'https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run',
headers={'Authorization': 'Bearer mwt_live_YOUR_KEY'},
json={'mode': 'variances', 'sd_1': 12.5, 'sd_2': 8.4, 'n_1': 25, 'n_2': 20, 'alpha': 0.05, 'tail': 'two'},
)
resp.raise_for_status()
data = resp.json()
print(data)
const resp = await fetch(
'https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run',
{
method: 'POST',
headers: {
'Authorization': 'Bearer mwt_live_YOUR_KEY',
'Content-Type': 'application/json',
},
body: JSON.stringify({"mode":"variances","sd_1":12.5,"sd_2":8.4,"n_1":25,"n_2":20,"alpha":0.05,"tail":"two"}),
}
);
const data = await resp.json();
console.log(data);
<?php
$ch = curl_init('https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run');
curl_setopt_array($ch, [
CURLOPT_POST => true,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'Authorization: Bearer mwt_live_YOUR_KEY',
'Content-Type: application/json',
],
CURLOPT_POSTFIELDS => json_encode([
'mode' => 'variances',
'sd_1' => 12.5,
'sd_2' => 8.4,
'n_1' => 25,
'n_2' => 20,
'alpha' => 0.05,
'tail' => 'two'
]),
]);
$resp = curl_exec($ch);
curl_close($ch);
print_r(json_decode($resp, true));
require 'net/http'
require 'json'
require 'uri'
uri = URI('https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = (uri.scheme == 'https')
req = Net::HTTP::Post.new(uri)
req['Authorization'] = 'Bearer mwt_live_YOUR_KEY'
req['Content-Type'] = 'application/json'
req.body = {
'mode' => 'variances',
'sd_1' => 12.5,
'sd_2' => 8.4,
'n_1' => 25,
'n_2' => 20,
'alpha' => 0.05,
'tail' => 'two'
}.to_json
resp = http.request(req)
puts JSON.parse(resp.body).inspect
package main
import (
"bytes"
"encoding/json"
"fmt"
"io"
"net/http"
)
func main() {
body, _ := json.Marshal(map[string]interface{}{
"mode": "variances",
"sd_1": 12.5,
"sd_2": 8.4,
"n_1": 25,
"n_2": 20,
"alpha": 0.05,
"tail": "two",
})
req, _ := http.NewRequest("POST", "https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run", bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer mwt_live_YOUR_KEY")
req.Header.Set("Content-Type", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil { panic(err) }
defer resp.Body.Close()
out, _ := io.ReadAll(resp.Body)
fmt.Println(string(out))
}
import java.net.URI;
import java.net.http.*;
var client = HttpClient.newHttpClient();
var req = HttpRequest.newBuilder()
.uri(URI.create("https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run"))
.header("Authorization", "Bearer mwt_live_YOUR_KEY")
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString("{\"mode\":\"variances\",\"sd_1\":12.5,\"sd_2\":8.4,\"n_1\":25,\"n_2\":20,\"alpha\":0.05,\"tail\":\"two\"}"))
.build();
var resp = client.send(req, HttpResponse.BodyHandlers.ofString());
System.out.println(resp.body());
Copy this into Claude Code, Cursor, Codex, Aider or Cline. It carries the endpoint,
the full schema, a sample response, and the credit rules — so the agent wires
f-test-f-distribution-calculator up correctly without draining your key.
POST /v1/tools/f-test-f-distribution-calculator/dry-run, which validates
the request and returns the response shape for
0 credits. Only the final confirmation call is billed
(1 credit).
/tools/f-test-f-distribution-calculator/prompt.md
(?variant=cursor / ?variant=mcp).
Integrate the MiniWebtool F-Test / F-Distribution Calculator API into this project.
## Your task
1. Read the reference below.
2. Ask me where this belongs in the codebase if it is not obvious.
3. Write the integration in the language and style of the surrounding code:
a small typed client function, errors handled, key read from the
environment (never hard-coded, never committed).
4. Verify with `/dry-run` first, then exactly one live call.
5. Show me the diff and the live result.
## Credit budget — follow these exactly
This API is metered. A live call costs 1 credit; the free tier
includes 1,000 credits per month. Burning them during integration is the
single most common way to waste this key.
1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the
payload for real and returns a sample result with the exact response shape.
Iterate there until your request builds and your parsing works.
2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once
dry-run passes. Print the result, then stop.
3. **Never call the API from unit tests, examples, or a retry loop.** Assert
against the sample response captured from `/dry-run` instead.
4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807
`application/problem+json` and says exactly what is wrong.
5. **On 429, honour `Retry-After`** and back off; do not tighten the loop.
6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50,
stop making live calls and tell me.
7. If the integration needs repeated calls at runtime, **cache by input** — this
tool is deterministic, so the same input always returns the same output.
## The API
**F-Test / F-Distribution Calculator** — Compare two variances with an F test, or turn an F statistic into a p-value and critical values.
- Live endpoint: `POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run` — costs 1 credit
- Dry run: `POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/dry-run` — costs 0 credits, same auth and validation
- Auth: `Authorization: Bearer <MINIWEBTOOL_API_KEY>`
- Content type: `application/json`
- Tool version: `2026-04-22` (output shape is stable within a major version)
- Full machine-readable spec: `https://api.miniwebtool.com/v1/openapi.json`
### Request body
| field | type | required | notes |
|---|---|---|---|
| `mode` | str | no | one of: variances, samples, statistic — variances \| samples \| statistic (default `variances`) |
| `sd_1` | float | no | sample 1 standard deviation (variances mode) (default `12.5`) |
| `sd_2` | float | no | sample 2 standard deviation (variances mode) (default `8.4`) |
| `n_1` | int | no | sample 1 size (variances mode) (default `25`) |
| `n_2` | int | no | sample 2 size (variances mode) (default `20`) |
| `sample_1` | str | no | comma-separated data (samples mode) |
| `sample_2` | str | no | comma-separated data (samples mode) |
| `f_value` | float | no | F statistic (statistic mode) (default `2.5`) |
| `df_1` | int | no | numerator degrees of freedom (statistic mode) (default `10`) |
| `df_2` | int | no | denominator degrees of freedom (statistic mode) (default `12`) |
| `alpha` | float | no | significance level (default `0.05`) |
| `tail` | str | no | one of: two, right — two \| right (default `two`) |
Example request body:
```json
{
"mode": "variances",
"sd_1": 12.5,
"sd_2": 8.4,
"n_1": 25,
"n_2": 20,
"alpha": 0.05,
"tail": "two"
}
```
### Response envelope
```json
{
"request_id": "req_01H…",
"tool": "f-test-f-distribution-calculator",
"tool_version": "2026-04-22",
"credits_used": 1,
"result": {
"mode": "variances",
"tail": "two-tailed",
"f_statistic": 2.214427,
"df_numerator": 24,
"df_denominator": 19,
"variance_1": 156.25,
"variance_2": 70.56,
"variance_ratio": 2.214427,
"p_value": 0.08117838,
"alpha": 0.05,
"critical_value_upper": 2.452321,
"critical_value_lower": 0.426411,
"reject_null": false,
"conclusion": "Fail to reject the null hypothesis: no significant difference in variances.",
"null_hypothesis": "variance_1 = variance_2",
"critical_table": [
{
"alpha": 0.1,
"critical_value": 1.787307
},
{
"alpha": 0.05,
"critical_value": 2.114143
},
{
"alpha": 0.025,
"critical_value": 2.452321
},
{
"alpha": 0.01,
"critical_value": 2.924866
},
{
"alpha": 0.005,
"critical_value": 3.306153
},
{
"alpha": 0.001,
"critical_value": 4.288111
}
]
}
}
```
`result` holds the tool output. Errors come back as
`application/problem+json` with `type`, `title`, `status`, and `detail`.
### Getting a key
If `MINIWEBTOOL_API_KEY` is not already in the environment, stop and ask me for
one — do not sign up, scrape, or guess a key. Free keys: https://api.miniwebtool.com/dashboard/
Integrate the MiniWebtool F-Test / F-Distribution Calculator API into this project.
## Your task
1. Read the reference below.
2. Ask me where this belongs in the codebase if it is not obvious.
3. Write the integration in the language and style of the surrounding code:
a small typed client function, errors handled, key read from the
environment (never hard-coded, never committed).
4. Verify with `/dry-run` first, then exactly one live call.
5. Show me the diff and the live result.
## Credit budget — follow these exactly
This API is metered. A live call costs 1 credit; the free tier
includes 1,000 credits per month. Burning them during integration is the
single most common way to waste this key.
1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the
payload for real and returns a sample result with the exact response shape.
Iterate there until your request builds and your parsing works.
2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once
dry-run passes. Print the result, then stop.
3. **Never call the API from unit tests, examples, or a retry loop.** Assert
against the sample response captured from `/dry-run` instead.
4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807
`application/problem+json` and says exactly what is wrong.
5. **On 429, honour `Retry-After`** and back off; do not tighten the loop.
6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50,
stop making live calls and tell me.
7. If the integration needs repeated calls at runtime, **cache by input** — this
tool is deterministic, so the same input always returns the same output.
## The API
**F-Test / F-Distribution Calculator** — Compare two variances with an F test, or turn an F statistic into a p-value and critical values.
- Live endpoint: `POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run` — costs 1 credit
- Dry run: `POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/dry-run` — costs 0 credits, same auth and validation
- Auth: `Authorization: Bearer <MINIWEBTOOL_API_KEY>`
- Content type: `application/json`
- Tool version: `2026-04-22` (output shape is stable within a major version)
- Full machine-readable spec: `https://api.miniwebtool.com/v1/openapi.json`
### Request body
| field | type | required | notes |
|---|---|---|---|
| `mode` | str | no | one of: variances, samples, statistic — variances \| samples \| statistic (default `variances`) |
| `sd_1` | float | no | sample 1 standard deviation (variances mode) (default `12.5`) |
| `sd_2` | float | no | sample 2 standard deviation (variances mode) (default `8.4`) |
| `n_1` | int | no | sample 1 size (variances mode) (default `25`) |
| `n_2` | int | no | sample 2 size (variances mode) (default `20`) |
| `sample_1` | str | no | comma-separated data (samples mode) |
| `sample_2` | str | no | comma-separated data (samples mode) |
| `f_value` | float | no | F statistic (statistic mode) (default `2.5`) |
| `df_1` | int | no | numerator degrees of freedom (statistic mode) (default `10`) |
| `df_2` | int | no | denominator degrees of freedom (statistic mode) (default `12`) |
| `alpha` | float | no | significance level (default `0.05`) |
| `tail` | str | no | one of: two, right — two \| right (default `two`) |
Example request body:
```json
{
"mode": "variances",
"sd_1": 12.5,
"sd_2": 8.4,
"n_1": 25,
"n_2": 20,
"alpha": 0.05,
"tail": "two"
}
```
### Response envelope
```json
{
"request_id": "req_01H…",
"tool": "f-test-f-distribution-calculator",
"tool_version": "2026-04-22",
"credits_used": 1,
"result": {
"mode": "variances",
"tail": "two-tailed",
"f_statistic": 2.214427,
"df_numerator": 24,
"df_denominator": 19,
"variance_1": 156.25,
"variance_2": 70.56,
"variance_ratio": 2.214427,
"p_value": 0.08117838,
"alpha": 0.05,
"critical_value_upper": 2.452321,
"critical_value_lower": 0.426411,
"reject_null": false,
"conclusion": "Fail to reject the null hypothesis: no significant difference in variances.",
"null_hypothesis": "variance_1 = variance_2",
"critical_table": [
{
"alpha": 0.1,
"critical_value": 1.787307
},
{
"alpha": 0.05,
"critical_value": 2.114143
},
{
"alpha": 0.025,
"critical_value": 2.452321
},
{
"alpha": 0.01,
"critical_value": 2.924866
},
{
"alpha": 0.005,
"critical_value": 3.306153
},
{
"alpha": 0.001,
"critical_value": 4.288111
}
]
}
}
```
`result` holds the tool output. Errors come back as
`application/problem+json` with `type`, `title`, `status`, and `detail`.
### Getting a key
If `MINIWEBTOOL_API_KEY` is not already in the environment, stop and ask me for
one — do not sign up, scrape, or guess a key. Free keys: https://api.miniwebtool.com/dashboard/
---
description: MiniWebtool F-Test / F-Distribution Calculator API — usage and credit budget
globs:
alwaysApply: false
---
# MiniWebtool F-Test / F-Distribution Calculator API
## The API
**F-Test / F-Distribution Calculator** — Compare two variances with an F test, or turn an F statistic into a p-value and critical values.
- Live endpoint: `POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run` — costs 1 credit
- Dry run: `POST https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/dry-run` — costs 0 credits, same auth and validation
- Auth: `Authorization: Bearer <MINIWEBTOOL_API_KEY>`
- Content type: `application/json`
- Tool version: `2026-04-22` (output shape is stable within a major version)
- Full machine-readable spec: `https://api.miniwebtool.com/v1/openapi.json`
### Request body
| field | type | required | notes |
|---|---|---|---|
| `mode` | str | no | one of: variances, samples, statistic — variances \| samples \| statistic (default `variances`) |
| `sd_1` | float | no | sample 1 standard deviation (variances mode) (default `12.5`) |
| `sd_2` | float | no | sample 2 standard deviation (variances mode) (default `8.4`) |
| `n_1` | int | no | sample 1 size (variances mode) (default `25`) |
| `n_2` | int | no | sample 2 size (variances mode) (default `20`) |
| `sample_1` | str | no | comma-separated data (samples mode) |
| `sample_2` | str | no | comma-separated data (samples mode) |
| `f_value` | float | no | F statistic (statistic mode) (default `2.5`) |
| `df_1` | int | no | numerator degrees of freedom (statistic mode) (default `10`) |
| `df_2` | int | no | denominator degrees of freedom (statistic mode) (default `12`) |
| `alpha` | float | no | significance level (default `0.05`) |
| `tail` | str | no | one of: two, right — two \| right (default `two`) |
Example request body:
```json
{
"mode": "variances",
"sd_1": 12.5,
"sd_2": 8.4,
"n_1": 25,
"n_2": 20,
"alpha": 0.05,
"tail": "two"
}
```
### Response envelope
```json
{
"request_id": "req_01H…",
"tool": "f-test-f-distribution-calculator",
"tool_version": "2026-04-22",
"credits_used": 1,
"result": {
"mode": "variances",
"tail": "two-tailed",
"f_statistic": 2.214427,
"df_numerator": 24,
"df_denominator": 19,
"variance_1": 156.25,
"variance_2": 70.56,
"variance_ratio": 2.214427,
"p_value": 0.08117838,
"alpha": 0.05,
"critical_value_upper": 2.452321,
"critical_value_lower": 0.426411,
"reject_null": false,
"conclusion": "Fail to reject the null hypothesis: no significant difference in variances.",
"null_hypothesis": "variance_1 = variance_2",
"critical_table": [
{
"alpha": 0.1,
"critical_value": 1.787307
},
{
"alpha": 0.05,
"critical_value": 2.114143
},
{
"alpha": 0.025,
"critical_value": 2.452321
},
{
"alpha": 0.01,
"critical_value": 2.924866
},
{
"alpha": 0.005,
"critical_value": 3.306153
},
{
"alpha": 0.001,
"critical_value": 4.288111
}
]
}
}
```
`result` holds the tool output. Errors come back as
`application/problem+json` with `type`, `title`, `status`, and `detail`.
### Getting a key
If `MINIWEBTOOL_API_KEY` is not already in the environment, stop and ask me for
one — do not sign up, scrape, or guess a key. Free keys: https://api.miniwebtool.com/dashboard/
## Credit budget — follow these exactly
This API is metered. A live call costs 1 credit; the free tier
includes 1,000 credits per month. Burning them during integration is the
single most common way to waste this key.
1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the
payload for real and returns a sample result with the exact response shape.
Iterate there until your request builds and your parsing works.
2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once
dry-run passes. Print the result, then stop.
3. **Never call the API from unit tests, examples, or a retry loop.** Assert
against the sample response captured from `/dry-run` instead.
4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807
`application/problem+json` and says exactly what is wrong.
5. **On 429, honour `Retry-After`** and back off; do not tighten the loop.
6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50,
stop making live calls and tell me.
7. If the integration needs repeated calls at runtime, **cache by input** — this
tool is deterministic, so the same input always returns the same output.
Add the MiniWebtool MCP server to this project, then use the
`f-test-f-distribution-calculator` tool from it.
Server URL: https://api.miniwebtool.com/v1/mcp
Transport: HTTP (Streamable HTTP / JSON-RPC 2.0)
Auth header: `Authorization: Bearer <MINIWEBTOOL_API_KEY>`
Claude Code:
```bash
claude mcp add --transport http miniwebtool https://api.miniwebtool.com/v1/mcp \
--header "Authorization: Bearer $MINIWEBTOOL_API_KEY"
```
Or add it to the MCP config file your client uses:
```json
{
"mcpServers": {
"miniwebtool": {
"type": "http",
"url": "https://api.miniwebtool.com/v1/mcp",
"headers": { "Authorization": "Bearer ${MINIWEBTOOL_API_KEY}" }
}
}
}
```
Once connected, `tools/list` exposes `f-test-f-distribution-calculator` with its JSON Schema, so you can
call it directly instead of writing an HTTP client.
## Credit budget — follow these exactly
This API is metered. A live call costs 1 credit; the free tier
includes 1,000 credits per month. Burning them during integration is the
single most common way to waste this key.
1. **Do all wiring against `/dry-run`, which costs 0 credits.** It validates the
payload for real and returns a sample result with the exact response shape.
Iterate there until your request builds and your parsing works.
2. **Make at most ONE live `/run` call** — a single end-to-end confirmation once
dry-run passes. Print the result, then stop.
3. **Never call the API from unit tests, examples, or a retry loop.** Assert
against the sample response captured from `/dry-run` instead.
4. **On 4xx, fix the payload — do not retry.** The error body is RFC 7807
`application/problem+json` and says exactly what is wrong.
5. **On 429, honour `Retry-After`** and back off; do not tighten the loop.
6. **Read `X-MWT-Credits-Remaining`** on every response. If it drops below 50,
stop making live calls and tell me.
7. If the integration needs repeated calls at runtime, **cache by input** — this
tool is deterministic, so the same input always returns the same output.
https://api.miniwebtool.com/v1/tools/f-test-f-distribution-calculator/run
Authorization: Bearer <key> and Content-Type: application/json. Copy-paste snippets in 7 languages are under Code examples.
{request_id, tool, tool_version, credits_used, result}. The typed output lives in result.
Compare two variances with an F test, or turn an F statistic into a p-value and critical values. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.
1 credit per successful call. Failed calls (validation errors, 5xx) don't bill.
Required fields: (none). Full schema at /v1/openapi.json.
Yes — same input, same output, forever. Tool version 2026-04-22; output shape is stable within a major version.
Yes. Connect to https://api.miniwebtool.com/v1/mcp over the Model Context Protocol. The agent discovers `f-test-f-distribution-calculator` with its JSON Schema automatically, so the model can plan while MiniWebtool handles the exact tool result.
JSON with a stable envelope: `{request_id, tool, tool_version, credits_used, result}`. Errors are RFC 7807 `application/problem+json`.
Every endpoint on this site is also exposed via the
Model Context Protocol at
https://api.miniwebtool.com/v1/mcp.
Claude, Cursor, and any MCP-capable agent can discover this tool
(f-test-f-distribution-calculator)
and its JSON Schema automatically — no client codegen.
# List tools the agent can call
curl -s https://api.miniwebtool.com/v1/mcp \
-H 'Content-Type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' \
| jq '.result.tools[] | select(.name=="f-test-f-distribution-calculator")'