Join the #1 community for gun owners of the Northwest
We believe the 2nd Amendment is best defended through grass-roots organization, education, and advocacy centered around individual gun owners. It is our mission to encourage, organize, and support these efforts throughout Oregon, Washington, Idaho, Montana, and Wyoming.
Discuss firearms and all aspects of firearm ownership
Join others in organizing against anti-gun legislation
Find nearby gun shops, ranges, training, and other resources
Discover free outdoor shooting areas
Stay up to date on firearm-related events
Share photos and video with other members
...and much more!
standard
In statistics, the standard deviation (SD, also represented by the lower case Greek letter sigma σ for the population standard deviation or the Latin letter s for the sample standard deviation) is a measure that is used to quantify the amount of variation or dispersion of a set of data values. A low standard deviation indicates that the data points tend to be close to the mean (also called the expected value) of the set, while a high standard deviation indicates that the data points are spread out over a wider range of values.
The standard deviation of a random variable, 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 units as the data.
In addition to expressing the variability of a population, the standard deviation is commonly used to measure confidence in statistical conclusions. For example, the margin of error in polling data is determined by calculating the expected standard deviation in the results if the same poll were to be conducted multiple times. This derivation of a standard deviation is often called the "standard error" of the estimate or "standard error of the mean" when referring to a mean. It is computed as the standard deviation of all the means that would be computed from that population if an infinite number of samples were drawn and a mean for each sample were computed.
The standard deviation of a population and the standard error of a statistic derived from that population (such as the mean) are quite different but related (related by the inverse of the square root of the number of observations). The reported margin of error of a poll is computed from the standard error of the mean (or alternatively from the product of the standard deviation of the population and the inverse of the square root of the sample size, which is the same thing) and is typically about twice the standard deviation—the half-width of a 95 percent confidence interval.
In science, many researchers report the standard deviation of experimental data, and only effects that fall much farther than two standard deviations away from what would have been expected are considered statistically significant—normal random error or variation in the measurements is in this way distinguished from likely genuine effects or associations. The standard deviation is also important in finance, where the standard deviation on the rate of return on an investment is a measure of the volatility of the investment.
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).
Gen 2 6.9” threaded barrel, will include everything except the lower as it has already sold. Looking to get $800 out of it (lowers usually run between three and four hundred). In great shape, only take to the range one time (about 200ish rounds). Small chip on Handguard finish from crappy B&T...
Looking to trade this RIA 1911 with another pistol or a lever action rifle. If you have any other interesting trade feel free to send a PM and ask. I would prefer to trade with another firearm though. Comes with the box and 3 8-round magazines, one factory two others I purchased later.
Target Sports USA has CCI Standard Velocity 22lr 40gr lead round nose for $400 for 5,000 with free shipping and handling. If you have their prime membership ($95 a year) it's $367.91 for 5,000...
Rock Island M1911-A1 CS
45ACP - 3.5” Barrel
1 - 7 Round Magazine
Hogue Wraparound Grips w/Finger Grooves
Kydex OWB holster
100 rounds Winchester Target Ammo
10 rounds Hornady Critical Defense Ammo
No box or manual
Gun is in excellent condition.
I took this in trade a while back so I don’t know...
Hi there,
For sale here is my Browning Buck Mark URX .22LR pistol. Original owner, no issues, shot infrequently and in great condition. It's a very accurate .22LR pistol, which is why I purchased it. Would keep it but am looking for a .22LR suppressor host so this is funding that search...
Taken on one range trip, worked excellent but need money for other things at the moment. Has minor cosmetic wear in end plate from previous brace installation along with a small chip on the finish of the top rail from where the front sight sits, but aside from that it is in perfect shape. Does...
the last generation of these GI style mags as the company is stopping production. lightweight and very nice feeding. these are new, and come sealed. Local pickup only.
OK so here's the jist: Washington residents take priority until July 1st.
30 rounders. 2nd gen PMAGs. Still in packaging. I can ship as long as you buy at least 5. These are the very boring looking, no window opaque plastic, ultra reliable PMAGs. Stack em dep before July 1st boys. I...
Selling my .22 revolver for cash for computer parts. Works and shoots accurate. Nickel plating is peeling in some places. Willing to trade for .44 magnum ammo.
Was cruising around and saw one of my preferred ammo vendors, Target Sports USA, had one of my preferred ammos in stock for a reasonable price. CCI Standard Velocity 22lr 40gr lead round nose for $425 for 5,000 with free shipping and handling. Pre-pandemic, this would have probably been around...
HI STANDARD 10 RND 22 LR USED MAGAZINE. CLEAN, STRONG SPRING, DOES NOT BIND ON RETRACTION. Pick Up in Portland Metro
WILL SHIP FOR $7 FIRST CLASS POSTAGE
Up for grabs is a great condition (given its age) High standard 12ga Riot shotgun! Takes 2 3/4 shells and has an action as smooth as butter also been told this slam fire (never personally tested).
$430
Fun fact this was the shotgun that Steve McQueen was using in the movie the getaway!
Buyer...
Looking to trade, mainly looking for the same or similar High standard but with a shorter barrel. A double 9 would be neat too. Not looking to trade it for anything else, and I’ll probably just keep it if I can’t find what I’m looking for. Let me know if you’re interested!
Up for grabs is an awesome condition high standard riot 12ga. Was a police trade in but, doesn’t appear to been used very much if at all! Has the rare leaf rifle sights, holds 6+1, has a buttery smooth action, and been told these slam fire (if your into that kind of thing.) $575 or trade for a...