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Yenza umgama woxanduva wokuba nguphakathi ukusuka kumzekelo ophakathi, SD nobungakanani.
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Malunga nale Calculator
A confidence interval gives a range that is likely to contain the true population mean, estimated from a sample. Instead of a single best guess it reports a band together with a confidence level that says how often such bands capture the true value.
This calculator uses the z-interval: mean ± z*·(σ / √n), where z* is the standard-normal critical value for your chosen confidence level (1.645 for 90%, 1.96 for 95%, 2.576 for 99%) and σ / √n is the standard error. It reports the bounds, the margin of error and the standard error, and a table shows the interval at the 90%, 95% and 99% levels so you can see how the range widens as you demand more confidence.
Worked example: a sample mean of 100 with a standard deviation of 15 and 50 observations has a standard error of 15 ÷ √50 ≈ 2.12. At 95% confidence the margin is 1.96 × 2.12 ≈ 4.16, giving an interval of about 95.84 to 104.16. The z-interval suits large samples (roughly n ≥ 30) or a known population standard deviation; for small samples use a t-interval instead.
Imibuzo ebuza rhoqo
Yintoni ethetha ukuba i-95% confidence interval?
Oku kuthetha ukuba ukuba uphinde uthathe isampuli amaxesha amaninzi kwaye ukwakha umda ixesha ngalinye, malunga ne 95% yale mimandla izakuqulathela umda woqoqosho. Oku akuthethi ukuba kukho i 95% ukwenzeka ukuba umda ukhona kulo mda omnye.
Ndifanele ndisebenzise ixesha lokuphumla le-t ntoni?
Sebenzisa umda we t xa umzekelo uncinci (ungaphantsi kwe 30) kwaye utshintsho lomlinganiselo woqoqosho aluziwa. Unikezelo lwe t lunomsila onzima, unika umda obanzi, okhuselekileyo ngakumbi kunale z- esekelwe enye.
Yintoni umda wemposiso kwixesha loxolo?
Umda wemposiso ngububanzi obuphakathi koluhlu, z* ·( σ / √n). Udibanisa nokukhupha ukusuka kwisampuli ephakathi ukufumana umda ophezulu nophantsi, ngoko umda omncinci uthetha ubalo oluchanekileyo.
Ndiyenza njani ithuba lokhuseleko elifutshane?
Collect a larger sample, since the width shrinks with the square root of n, or accept a lower confidence level. Reducing the variability in your data also tightens the interval. Quadrupling the sample size roughly halves the width.
Ingaba umphakamo ophezulu woxanduva uyenza ithuba libanzi?
Ewe. Ukufuna uxanduva oluninzi lusebenzisa ixabiso elibalulekileyo elikhulu z *, ngoko u99% wokungafani kubanzi kune 95% wokungafani owenziwe kwi data efanayo. Kusoloko kukho urhwebo phakathi koxanduva kunye nobuchanekileyo.
Yintoni impazamo eqhelekileyo?
Imposiso eqhelekileyo yindawo eqhelekileyo yokutshintsha yahlulahlulwe yisiseko esikwere sobungakanani besampuli (σ / √n). Ilinganisela ukuba isampuli iphakathi ngokwayo iyahluka ukusuka kumlinganiselo ukuya kumlinganiselo, kwaye iyi block yokwakha yomda wemposiso.
API — sebenzisa le calculator ukusuka kwikhowudi
Nceda le khadi lemali njengendawo esemva ye-JSON ekhululekileyo - akukho qhosha lifunekayo. Thumela amaxabiso endawo ezantsi njengeparameter yombuzo okanye i-JSON. Nantoni na oyenzayo isebenzisa okungagqibekanga okufanayo eli phepha ligqityiwe ngaphambili; iparameter engaziwayo yi 400, ayikho i zero ekhululekileyo. Funda i-API epheleleyo →
Incopho yesiphelo
GET https://calculator.free/api/v1/confidence-interval/curl
curl "https://calculator.free/api/v1/confidence-interval/?mean=100&sd=15&n=50&conf=1.96"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/confidence-interval/?" + new URLSearchParams({
"mean": "100",
"sd": "15",
"n": "50",
"conf": "1.96"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.