Nhazi
Kewapụta n'etiti maka n'etiti site n'ụdị n'etiti, SD na ụhara.
Nhọrọ ndị ahụ ga-akpụzi mgbe ị na-etipụta.
N'ihe banyere calculator a
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.
Ajụjụ ndị a na-ajụkarị
Gịnị bụ 95% confidence interval?
Ọ pụtara na ọ bụrụ na ị na-ebuli n'ọdịnihu oge ọbụla na-ebubata n'etiti oge ọbụla, ihe dịka 95% nke n'etiti oge ahụ ga-echekwa n'etiti ndị mmadụ. Ọ bụghị ihe ọ pụtara bụ na ọ bụ 95% nke n'etiti n'etiti oge a.
Kedụ mgbe m ga-eji t-interval na-eme ya?
Jiri t-interval mgbe sample dị obere (n'okpuru 30) na ndịna-adabaghị n'ihe nlereanya. T-nhazi ahụ nwere ụda dị n'ime, na-enye obere n'ime, n'etiti nke a z-n'isi.
Gịnị bụ n'ime nke a na-agaghị eme n'ime n'etiti n'etiti?
Ogo nke nsogbu bụ nke ọkara-uwe nke n'etiti, z*· (σ / √n). I ga-agbakwunye na wepu ya site na nlele ahụ iji nweta elu na ala n'oche, yabụ ogo nke obere pụtara n'ihe nlereanya nke dị n'oche.
Olee otú m ga-esi mee ka n'etiti n'
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.
Ọ bụrụ na elu nrụnye na-eme ka n'etiti dị n'ime?
Ee. Ikwesiri nkwenye kasị ukwuu na-eji nnukwu uru z*, ya mere 99% n'etiti bụ n'etiti nke 95% mepụtara site na data nke otu. E nwere mgbe niile n'etiti nkwenye na nghọta.
Gịnị bụ ụgha n'ozuzu ya?
Nhazi asị bụ nhazi asị nke a haziri site na square nwuo nke nha saịlọn (σ / √n). O mepụtara na ọ ga-adabere n'ụdị saịlọn ahụ n'onwe ya site na saịlọn ruo na saịlọn, na ọ bụ arụpụtaghị blọgụ nke margin nke asị.
API — jiri kaadị a site na kóòdù
Kpọọ kalkulata a dịka ebe ngwụcha JSON n'efu - enweghị kii achọrọ. Ziga valiu ebe ahụ n'okpuru dịka paramita ajụjụ mọọbụ JSON. Ihe ọbụla ị na-ewepụ na-eji dìfọ́ọ̀ltụ̀ nke a na-edebe ihuakwụkwọ a na ya; parameter a na-amaghị bụ 400, ọ dịghị sẽọ̀rọ̀. Gụọ ngwe ndị ahụ niile →
Ebemkpofuozi
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);Ihe a na-ahụta bụ n'ihi nlekọta n'ozuzu ya, ọ bụghị nlekọta ego, ọgwụ ma ọ bụ nlekọta ego.