Standard Deviation Calculate vs 情侣小日常

In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values.A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the values are spread out over a wider range. Standard deviation may be abbreviated SD, and is most commonly represented in mathematical texts and equations by the lower case Greek letter sigma σ, for the population standard deviation, or the Latin letter s, for the sample standard deviation. Application examples The practical value of understanding the standard deviation of a set of values is in appreciating how much variation there is from the average (mean). Experiment, industrial and hypothesis testing[ Standard deviation is often used to compare real-world data against a model to test the model. For example, in industrial applications the weight of products coming off a production line may need to comply with a legally required value. By weighing some fraction of the products an average weight can be found, which will always be slightly different from the long-term average. By using standard deviations, a minimum and maximum value can be calculated that the averaged weight will be within some very high percentage of the time (99.9% or more). If it falls outside the range then the production process may need to be corrected. Statistical tests such as these are particularly important when the testing is relatively expensive. For example, if the product needs to be opened and drained and weighed, or if the product was otherwise used up by the test. In experimental science, a theoretical model of reality is used. Particle physics conventionally uses a standard of "5 sigma" for the declaration of a discovery. A five-sigma level translates to one chance in 3.5 million that a random fluctuation would yield the result. This level of certainty was required in order to assert that a particle consistent with the Higgs boson had been discovered in two independent experiments at CERN,also leading to the declaration of the first observation of gravitational waves, and confirmation of global warming. Weather As a simple example, consider the average daily maximum temperatures for two cities, one inland and one on the coast. It is helpful to understand that the range of daily maximum temperatures for cities near the coast is smaller than for cities inland. Thus, while these two cities may each have the same average maximum temperature, the standard deviation of the daily maximum temperature for the coastal city will be less than that of the inland city as, on any particular day, the actual maximum temperature is more likely to be farther from the average maximum temperature for the inland city than for the coastal one. Finance In finance, standard deviation is often used as a measure of the risk associated with price-fluctuations of a given asset (stocks, bonds, property, etc.), or the risk of a portfolio of assets (actively managed mutual funds, index mutual funds, or ETFs). Risk is an important factor in determining how to efficiently manage a portfolio of investments because it determines the variation in returns on the asset and/or portfolio and gives investors a mathematical basis for investment decisions (known as mean-variance optimization). The fundamental concept of risk is that as it increases, the expected return on an investment should increase as well, an increase known as the risk premium. In other words, investors should expect a higher return on an investment when that investment carries a higher level of risk or uncertainty. When evaluating investments, investors should estimate both the expected return and the uncertainty of future returns. Standard deviation provides a quantified estimate of the uncertainty of future returns.

最暖心的距离，是时时知道“TA在哪里”。 最甜蜜的日常，是共同记录“我们的故事”。 是否曾有过这样的时刻？ · 想知道TA是否安全到家，却又怕频繁打电话打扰？ · 翻遍手机，却发现没有一块专属于你们的甜蜜空间？ · 忙于生活，不小心错过了那个意义非凡的纪念日？ · 感觉恋爱久了，缺少了点共同完成目标的新鲜感？ · 别让忙碌和距离，稀释了你们之间的浓情蜜意。 “情侣小日常”———专为亲密关系设计的温暖空间。 在这里，我们用科技守护爱情，让每一次互动都成为滋养感情的养分。 我们不仅仅是一个App，更是你们爱情的“数字管家”和“私密花园”。 【实时位置共享 · 给予心安，而非猜疑】 · “你到哪儿了？” 从此变成温柔的牵挂。无需反复询问，一眼可见TA的实时位置。 · 精准守护： 通勤路上、出差途中，随时知晓对方安全抵达，让担心变为安心。 · 隐私至上： 共享权限完全由您掌控，可随时开启或关闭，守护亲密也尊重独立。 【情侣日记互动 · 打造只属于你们的回忆银行】 · 你们的悄悄话、甜蜜瞬间、旅行打卡……终于有了一个不会被朋友圈淹没的专属领地。 · 双向记录： 共同编辑同一篇日记，从“我和你”的角度，拼凑出完整的爱的记忆。 · 多媒体珍藏： 用文字、照片、视频，将心动瞬间永久封存。这里是你们最高颜值的恋爱博物馆。 【纪念日提醒 · 不再错过每一个重要日子】 · 恋爱100天、一周年、她的生日……所有重要日子，我们帮你牢记。 · 智能倒数： 充满期待的纪念日倒数，让幸福感提前升温。 · 温馨提醒： 提前推送通知，给你充足时间为TA准备惊喜，告别“忘记纪念日”的尴尬危机。 【情侣任务 · 创造共同成长的乐趣】 · 为你们的感情注入新鲜感和目标感，一起完成挑战，让爱在协作中升温。 · 自定义任务： 共同设定目标，比如“本周一起看一部电影”、“共同储蓄计划”、“学会一道新菜”。 · 成就系统： 每完成一个任务，收获满满的成就感和专属徽章，让平淡日常充满游戏般的乐趣。 我们已经为你准备好了所有增进感情的工具， 现在，只差一个你和TA。 立即下载“情侣小日常”， 开启你们更甜蜜、更紧密的恋爱新篇章。 [自动续费会员] --订阅周期: 月/季/年 --付款方式:当用户确认购买并付款后记入iTunes账单 --续订: Apple iTunes账户会在当前订阅周期 24小时内扣除下一次的订阅费用，扣除成功后订阅自动延长一个周期 --取消续订:如需取消自动续订，应在当前订阅到期24小时之前前往Apple ID/iTunes 内关闭自动续订功能 隐私政策：https://jp.sdoc.ink/web/#/p/7d1533619b7650c3ff21227e0752ff60 用户协议：https://jp.sdoc.ink/web/#/p/65ace5242c79a571b8a37826cec9b4f3 付费协议：https://jp.sdoc.ink/web/#/p/65f26d951847012f49d8133ac4c6d243