STD meaning in Maths ?

Answer: What is Standard Deviation mean?

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.

The standard deviation of a random variable, sample, statistical population, data set, or probability distribution is the square root of its variance. It is algebraically simpler, though in practice, less robust than the average absolute deviation. A useful property of the standard deviation is that unlike the variance, it is expressed in the same unit as the data.

The standard deviation of a population or sample and the standard error of a statistic (e.g., of the sample mean) are quite different, but related. The sample mean's standard error is the standard deviation of the set of means that would be found by drawing an infinite number of repeated samples from the population and computing a mean for each sample. The mean's standard error turns out to equal the population standard deviation divided by the square root of the sample size, and is estimated by using the sample standard deviation divided by the square root of the sample size. For example, a poll's standard error (what is reported as the margin of error of the poll), is the expected standard deviation of the estimated mean if the same poll were to be conducted multiple times. Thus, the standard error estimates the standard deviation of an estimate, which itself measures how much the estimate depends on the particular sample that was taken from the population.

In science, it is common to report both the standard deviation of the data (as a summary statistic) and the standard error of the estimate (as a measure of potential error in the findings). By convention, only effects more than two standard errors away from a null expectation are considered "statistically significant", a safeguard against spurious conclusion that is really due to random sampling error.

When only a sample of data from a population is available, the term standard deviation of the sample or sample standard deviation can refer to either the above-mentioned quantity as applied to those data, or to a modified quantity that is an unbiased estimate of the population standard deviation (the standard deviation of the entire population).

reference

Full Form	Category
Strategic Technical Directorate	Academic & Science
Sigma Tau Delta	Academic & Science
Stop, Treat, and Destroy	Academic & Science
Salinity, Temperature, and Depth	Academic & Science
Santo Domingo	Airport Code
Stuart Tyrrell Developments (Company)	Business
Skip Tooth Design	Business
Software Tool and Die	Business
Short Term Debt	Business
Subscribers Trunk Dialling	Business
Banco Santander Cent Hispano	Business
Someone Truly Divine	Community
Selling The Drama	Community
Substitute Trustee's Deed	Community
Scriptures Temple Dating	Community
Simon Tissot Dupont	Community
Short Tiny Dancers	Community
Simplified Trellis Decoder	Computer and Networking
Set Direction Flag	Computer Assembly Language
Software Test Document	Computer Technology
Spyro The Dragon	Computing
Semantic Type Definition	Computing
Super Twist Display	Computing
Suspend To Disk	Computing
Save To Disk	Computing
Set Direction	Computing
Selection Transmit Diversity	Computing
Synchronous Time Division	Computing
Store Indirect to Data Space	Computing
State Transition Diagram	Computing
Save The Date	Computing
Dobra	Country Currency
Stadium	Cryptocurrency
Sexually Transmitted Diseases	Disease
Sexualy Transmited Disease	Disease
Doctor of Sacred Theology	Educational Degree
Sacrae Theologiae Doctor	Educational Degree
Locoscript Standard	File Type
State Transition Diagram Graphics File	File Type
Short Term of Duty	General
Star Trek Discovery	General
Sunbeam Talbot Darracq	General
Supertech Dino	General
Super Turbo Diesel	General
Snails Taste Delicious	General
Scheduled Time of Departure	General
Solar Terrestrial Dispatch	General
Standard Trunk Dialing	General
Super Tool Destruction	General
Small Tiny Dogs	General
Standard Time Departure	General
Split The Difference	General
Staroffice Template Drawing	General
Shut The Door	General
Skinnies Trannies and Drops	General
Sao Tomean Dobra	General
Seize The Day	General
STD Transmitting Dinosaur	General
Super Toddler Drool	General
Stop The Disease	General
Started Trial Dog	General
Short Term Disability	Governmental
Severe Tire Damage	Governmental
Shoot The Dummy	Governmental
Syrian Terrorist Detector	Governmental
State Territory District	Governmental
SATROD	Indian Railway Station
Subarashii Tomodachi Doushi (means Best Friends)	International
Stunde	International
Small Trimaran Design	International
Saves The Day	Jobs
Standard Deviation	Maths
Standing Tremor Disorder	Medical
Skeletal Transcript Database	Medical
sexually transmitted disease—but	Medical
Sexual Transmitted Diseases	Medical
Sexual Transmitted Disease	Medical
Sheep Transmitted Disease	Medical
Sexual Tension Disorder	Medical
Small Testicle Disorder	Medical
Short-Term Depression	Medical
ST-segment depression	Medical
Sexually Transmitted Disease	Medical
Skin Test Dose	Medical
Sterilized Testing Developer	Medical
Sweet Translucent Dreams	Messaging
Some Thing Duh	Messaging
Soft Touch Denial	Messaging
Synthetic Training Device	Military and Defence
Software Test Description	Military and Defence
Sao Tome Dobra	Regional
Santo Domingo, Venezuela	Regional
Simple To Design	Softwares
Security Tools Distribution	Softwares
Shuttle Test Director	Space Science
Standard	Space Science
Standard Transmission Difficulties	Space Science
Subscriber Trunk Dialling	Telecommunication
Subscriber Trunk Dialing	Telecommunication
Secondary Telecom District	Telecommunication