{"id":1886,"date":"2021-03-03T13:01:39","date_gmt":"2021-03-03T13:01:39","guid":{"rendered":"https:\/\/quickpercentcalc.com\/tolfraedi\/fravik-reiknivel\/"},"modified":"2025-04-08T15:03:29","modified_gmt":"2025-04-08T15:03:29","slug":"fravik-reiknivel","status":"publish","type":"page","link":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/","title":{"rendered":"Fr\u00e1vik reikniv\u00e9l"},"content":{"rendered":"\n<p>Reikna\u00f0u fr\u00e1vik. Reikniv\u00e9lin okkar reiknar fr\u00e1viki\u00f0 fyrir \u00feig.<\/p>\n\n<p>Dreifni (s <sup>2<\/sup> ) er m\u00e6likvar\u00f0i \u00e1 dreifingu \u00ed talnar\u00f6\u00f0. Dreifni er veldi <a href=\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/stadalfravik-reiknivel\/\">sta\u00f0alfr\u00e1viksins<\/a> .<\/p>\n\n<p><strong>Skref til a\u00f0 reikna dreifni:<\/strong><br\/> 1. Finndu muninn \u00e1 hverri t\u00f6lu (x) og <a href=\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/medal-medaltal-reiknivel\/\">me\u00f0altalinu<\/a> ((stika{x} )).<br\/> 2. Ferningur (^2) hver munur<br\/> 3. Legg\u00f0u saman t\u00f6lurnar<br\/> 4. Deili\u00f0 me\u00f0 fj\u00f6lda gilda m\u00ednus 1<\/p>\n\n<p><\/p>\n\n<p>Til a\u00f0 nota \u00feessa reikniv\u00e9l skaltu a\u00f0greina hverja t\u00f6lu me\u00f0 bili (td 2 5 4 osfrv.). Fyrir aukastafi getur\u00f0u nota\u00f0 anna\u00f0 hvort kommu e\u00f0a punkt. Ekki nota \u00fe\u00fasund skilgreinar e\u00f0a stafi.<\/p>\n\n<p>Form\u00fala fyrir fr\u00e1vik:<\/p>\n\n<style>\n\n.frac {\n    display: inline-block;\n    position: relative;\n    vertical-align: middle;\n    letter-spacing: 0.001em;\n    text-align: center;\n}\n.frac > span {\n    display: block;\n    padding: 0.1em;\n}\n.frac span.bottom {\n    border-top: thin solid black;\n}\n.frac span.symbol {\n    display: none;\n}\n<\/style>\n\n<div class=\"formel\">\n  $${\\frac{1} {n-1} \\sum_{i=1}^N (x_i &#8211; \\yfirl\u00edna{x} )^2}$$\n<\/div>\n<br\/><br\/>\n\n<script src=\"https:\/\/ajax.googleapis.com\/ajax\/libs\/jquery\/3.5.1\/jquery.min.js\"><\/script>\n<script>\n    $(function () {\n        $(\"#regnut\").click(function () {\n            var str = $(\"#tall\").val();\n            var res = Array.from(str.split(\/[ ]+\/));\n            var utregning = Array;\n            var std;\n\n\n            for (var i = 0; i < res.length; i++) {\n                res[i] = res[i].replace(\",\", \".\");\n                res[i] = parseFloat(res[i]);\n            }\n\n            var total = 0;\n\n            for (var i = 0; i < res.length; i++) {\n                total = total + res[i];\n            }\n\n            \/\/mean\n            var gjsnitt = total \/ res.length;\n\n            \/\/difference between each number and mean\n            for (var i = 0; i < res.length; i++) {\n                utregning[i] = res[i] - gjsnitt;\n\n            }\n\n            for (var i = 0; i < res.length; i++) {\n                utregning[i] = Math.pow(utregning[i], 2);\n            }\n\n            \/\/sum of squares\n            var sumKv = 0;\n            for (var i = 0; i < res.length; i++) {\n                sumKv = sumKv + utregning[i];\n            }\n            console.log(sumKv);\n            \/\/calculate variance\n            std = sumKv \/ (res.length - 1);\n\n\n            if (std % 1 !== 0) {\n                std = std.toFixed(4);\n            }\n            else {\n                std = std.toFixed();\n            }\n\n            std = std.toString();\n            std = std.replace(\".\", \",\");\n\n            $(\"#resultat\").html(std);\n\n            $(\"#resultatBoks\").css({ \"visibility\": \"initial\" });\n\n\n        });\n\n\n    });\n\n<\/script>\n\n\n<label for=\"tall\">Talnar\u00f6\u00f0 (nota\u00f0u bil til a\u00f0 a\u00f0greina t\u00f6lur)<\/label><br\/><textarea type=\"text\" id=\"tall\"><\/textarea>\n<br\/><br\/><br\/><br\/>\n<input type=\"button\" id=\"regnut\" value=\"Reikna\u00f0u\"\/>\n<br\/><br\/><div id=\"resultatBoks\" style=\"visibility: hidden;\">\n    <span>Ni\u00f0ursta\u00f0a:<\/span><br\/>    <span id=\"resultat\" class=\"kalkyleResultat\"><\/span>\n<\/div>\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Reikna\u00f0u fr\u00e1vik. Reikniv\u00e9lin okkar reiknar fr\u00e1viki\u00f0 fyrir \u00feig. Dreifni (s 2 ) er m\u00e6likvar\u00f0i \u00e1 dreifingu \u00ed talnar\u00f6\u00f0. Dreifni er [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1706,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"kalkulator-side.php","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-1886","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Fr\u00e1vik reikniv\u00e9l - Quick Percent Calculator<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/\" \/>\n<meta property=\"og:locale\" content=\"is_IS\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Fr\u00e1vik reikniv\u00e9l - Quick Percent Calculator\" \/>\n<meta property=\"og:description\" content=\"Reikna\u00f0u fr\u00e1vik. Reikniv\u00e9lin okkar reiknar fr\u00e1viki\u00f0 fyrir \u00feig. Dreifni (s 2 ) er m\u00e6likvar\u00f0i \u00e1 dreifingu \u00ed talnar\u00f6\u00f0. Dreifni er [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/\" \/>\n<meta property=\"og:site_name\" content=\"Quick Percent Calculator\" \/>\n<meta property=\"article:modified_time\" content=\"2025-04-08T15:03:29+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/\",\"url\":\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/\",\"name\":\"Fr\u00e1vik reikniv\u00e9l - Quick Percent Calculator\",\"isPartOf\":{\"@id\":\"https:\/\/quickpercentcalc.com\/is\/#website\"},\"datePublished\":\"2021-03-03T13:01:39+00:00\",\"dateModified\":\"2025-04-08T15:03:29+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/#breadcrumb\"},\"inLanguage\":\"is\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/quickpercentcalc.com\/is\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"T\u00f6lfr\u00e6\u00f0i\",\"item\":\"https:\/\/quickpercentcalc.com\/is\/statistics\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Fr\u00e1vik reikniv\u00e9l\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/quickpercentcalc.com\/is\/#website\",\"url\":\"https:\/\/quickpercentcalc.com\/is\/\",\"name\":\"Quick Percent Calculator\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/quickpercentcalc.com\/is\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"is\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Fr\u00e1vik reikniv\u00e9l - Quick Percent Calculator","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/","og_locale":"is_IS","og_type":"article","og_title":"Fr\u00e1vik reikniv\u00e9l - Quick Percent Calculator","og_description":"Reikna\u00f0u fr\u00e1vik. Reikniv\u00e9lin okkar reiknar fr\u00e1viki\u00f0 fyrir \u00feig. Dreifni (s 2 ) er m\u00e6likvar\u00f0i \u00e1 dreifingu \u00ed talnar\u00f6\u00f0. Dreifni er [&hellip;]","og_url":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/","og_site_name":"Quick Percent Calculator","article_modified_time":"2025-04-08T15:03:29+00:00","twitter_card":"summary_large_image","twitter_misc":{"Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/","url":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/","name":"Fr\u00e1vik reikniv\u00e9l - Quick Percent Calculator","isPartOf":{"@id":"https:\/\/quickpercentcalc.com\/is\/#website"},"datePublished":"2021-03-03T13:01:39+00:00","dateModified":"2025-04-08T15:03:29+00:00","breadcrumb":{"@id":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/#breadcrumb"},"inLanguage":"is","potentialAction":[{"@type":"ReadAction","target":["https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/quickpercentcalc.com\/is\/tolfraedi\/fravik-reiknivel\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/quickpercentcalc.com\/is\/"},{"@type":"ListItem","position":2,"name":"T\u00f6lfr\u00e6\u00f0i","item":"https:\/\/quickpercentcalc.com\/is\/statistics\/"},{"@type":"ListItem","position":3,"name":"Fr\u00e1vik reikniv\u00e9l"}]},{"@type":"WebSite","@id":"https:\/\/quickpercentcalc.com\/is\/#website","url":"https:\/\/quickpercentcalc.com\/is\/","name":"Quick Percent Calculator","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/quickpercentcalc.com\/is\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"is"}]}},"_links":{"self":[{"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/pages\/1886","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/comments?post=1886"}],"version-history":[{"count":1,"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/pages\/1886\/revisions"}],"predecessor-version":[{"id":1887,"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/pages\/1886\/revisions\/1887"}],"up":[{"embeddable":true,"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/pages\/1706"}],"wp:attachment":[{"href":"https:\/\/quickpercentcalc.com\/is\/wp-json\/wp\/v2\/media?parent=1886"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}