{"id":1272,"date":"2021-08-23T18:48:25","date_gmt":"2021-08-23T18:48:25","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/?post_type=chapter&#038;p=1272"},"modified":"2022-01-28T20:35:33","modified_gmt":"2022-01-28T20:35:33","slug":"introduction-to-mean-or-expected-value-and-standard-deviation","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/chapter\/introduction-to-mean-or-expected-value-and-standard-deviation\/","title":{"raw":"Introduction to Mean or Expected Value and Standard Deviation","rendered":"Introduction to Mean or Expected Value and Standard Deviation"},"content":{"raw":"<h2>What you\u2019ll learn to do: understand and calculate the standard deviation of a discrete random variable<\/h2>\r\n<img class=\"alignright wp-image-1273 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5668\/2021\/08\/23183710\/pexels-pixabay-50692-300x200.jpg\" alt=\"Baby Sleeping Beside Girl on Gray Floral Textile\" width=\"300\" height=\"200\" \/>Although a family may have 0, 1, 2, 3 or more children, we often want to know how many children are in a family on average. Reporting that a family has 2.1 children may sound strange, but this is the long-term average based on selecting many families and not the number of children in an individual family. In this section, you will learn how to find the mean (or average) and standard deviation for a discrete random variable.","rendered":"<h2>What you\u2019ll learn to do: understand and calculate the standard deviation of a discrete random variable<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright wp-image-1273 size-medium\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/5668\/2021\/08\/23183710\/pexels-pixabay-50692-300x200.jpg\" alt=\"Baby Sleeping Beside Girl on Gray Floral Textile\" width=\"300\" height=\"200\" \/>Although a family may have 0, 1, 2, 3 or more children, we often want to know how many children are in a family on average. Reporting that a family has 2.1 children may sound strange, but this is the long-term average based on selecting many families and not the number of children in an individual family. In this section, you will learn how to find the mean (or average) and standard deviation for a discrete random variable.<\/p>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-1272\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li><strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Baby Sleeping Beside Girl on Gray Floral Textile. <strong>Authored by<\/strong>: Pixabay. <strong>Provided by<\/strong>: Pexels. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.pexels.com\/photo\/love-baby-boys-family-50692\/\">https:\/\/www.pexels.com\/photo\/love-baby-boys-family-50692\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/about\/cc0\">CC0: No Rights Reserved<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":169134,"menu_order":10,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Baby Sleeping Beside Girl on Gray Floral Textile\",\"author\":\"Pixabay\",\"organization\":\"Pexels\",\"url\":\"https:\/\/www.pexels.com\/photo\/love-baby-boys-family-50692\/\",\"project\":\"\",\"license\":\"cc0\",\"license_terms\":\"\"},{\"type\":\"original\",\"description\":\"\",\"author\":\"\",\"organization\":\"Lumen Learning\",\"url\":\"\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-1272","chapter","type-chapter","status-publish","hentry"],"part":240,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/chapters\/1272","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/wp\/v2\/users\/169134"}],"version-history":[{"count":2,"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/chapters\/1272\/revisions"}],"predecessor-version":[{"id":3548,"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/chapters\/1272\/revisions\/3548"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/parts\/240"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/chapters\/1272\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/wp\/v2\/media?parent=1272"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/pressbooks\/v2\/chapter-type?post=1272"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/wp\/v2\/contributor?post=1272"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/introstatscorequisite\/wp-json\/wp\/v2\/license?post=1272"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}