I-margin yephutha le-calculator
Thola umkhawulo wephutha lohlelo lokucwaninga.
Iziphetho zivuselelwa uma ubhala.
Malunga nale khadi
The margin of error tells you how far a survey result is likely to be from the true population value — the "plus or minus" figure quoted next to poll results. For a proportion it is z*·√(p(1 − p) / n), where p is the sample proportion, n the sample size and z* the critical value for your confidence level (1.96 for 95%).
It reports the margin, the confidence-interval bounds around your proportion and the full interval width, and a table shows how the margin shrinks as the sample grows. The default 50% proportion gives the most conservative (largest) margin, because the quantity p(1 − p) peaks at p = 0.5, which is why pollsters often quote it.
Worked example: with 1,000 respondents split 50/50 at 95% confidence, the margin is 1.96 × √(0.5 × 0.5 ÷ 1000) ≈ 1.96 × 0.0158 ≈ 3.1 percentage points. So a poll result of 50% really means somewhere between about 46.9% and 53.1%. To halve that margin you would need roughly four times the sample.
Imibuzo ebuzwa kaningi
Kungani isibonisi esincane sikhuphula umkhawulo wephutha?
Umkhawulo uncane nge-square root yesayizi yesampula, ngakho-ke ukuphinda kabili n uhlukanise umkhawulo wephutha. Lezo zibuyiselo ezincane zidinga ukuphinda umkhawulo ngaphansi kwengxenye yeshumi noma amaphuzu amabili.
Kungani 50% ibanga elizenzakalelayo?
Ubukhulu p(1 − p) bukhulu ku p = 0.5, ngakho-ke ukucabanga ukuthi 50/50 ukuhlukaniswa kwenza okubanzi kakhulu, okuningi okulondolozayo ibanga lephutha. Ukusebenzisa lokhu kuqinisekiswa ibanga eliqiniso alikho likhulu kunalelo elishicilelwe.
Ngiyibala kanjani ibanga lephutha?
Ukuphindaphinda ixabiso elibalulekile z * lomgangatho wakho wokuba nesiqiniseko ngesisekelo esingu-square se-p (1 − p) ÷ n. P = 0.5, n = 1000 nokwethemba okungu-95%, okuwu-1.96 × √ (0.25 ÷ 1000) ≈ 3.1 amaphuzu ephesenti.
Yini ushintsho phakathi kwe-margin yephutha nesikhathi sokwethemba?
I-margin yephutha yingxenye yobubanzi; isikhathi sokwethemba yisikhathi esigcwele esitholakele ngokungeza nokususa i-margin kusuka emiphumela yakho. I-48% yemiphumela ene-3-point margin inikeza isikhathi sokwethemba se-45% kuya ku-51%.
Ingabe inani elikhulu lentuthuko lidinga ibanga elikhulu lephutha?
Akunakwenzeka. Uma abantu abangaphezu kwamawaka ambalwa, ubukhulu beqembu lincane kakhulu, futhi alithintanga ibanga eliphakathi — okubalulekile wubukhulu besampula. Lokhu kusho ukuthi ucwaningo lwezwe kanye nocwaningo lwedolobha zingaba nebanga elifanayo, futhi zithole inani elifanayo labantu abaphendulayo.
Indlela ibanga lokuzithemba lishintsha ngayo ibanga lephutha?
Izinga eliphakeme lokuzithemba lisebenzisa i-z* enkulu, ebanzisa umkhawulo. Ukusuka ku-95% (z* = 1.96) kuya ku-99% (z* = 2.576) kunciphisa umkhawulo ngo-31% ngesibonelo esifanayo.
API — sebenzisa le calculator kusuka kukhodi
Nquma le calculator njenge JSON evulekile yendawo yokuqeda - akukho isithonjana esidingekayo. Thumela amaxabiso endawo ngezansi njengezilungiselelo zombuzo noma i-JSON. Noma yini ongayishiya isebenzisa iphutha elifanayo elifakwe ngaphambili lekhasi; ipharamitha engaziwa yi-400, ayikho i-zero emnyama. Funda i-API egcwele →
Ingxenye yendawo
GET https://calculator.free/api/v1/margin-of-error/curl
curl "https://calculator.free/api/v1/margin-of-error/?n=1000&p=50&conf=1.96"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/margin-of-error/?" + new URLSearchParams({
"n": "1000",
"p": "50",
"conf": "1.96"
}));
const data = await r.json();
console.log(data.results);Izibalo ziyisilinganiso esisetshenziswa ukuqondisa kuphela, hhayi ukucebisa ngezimali, ukwelashwa noma ukukhokha.