Statistical Science Web: Free Statistical Programs Statistical Computing Software for Population Analysis. A directory of software sources for analysing animal abundance. Gordon's choices: BUGS. Other packages: ADE-4. The Order of Operations: PEMDAS Purplemath If you are asked to simplify something like "4 + 2×3", the question that naturally arises is "Which way do I do this? Because there are two options!" I could add first: ...or I could multiply first: Which answer is the right one? MathHelp.com It seems as though the answer depends on which way you look at the problem. To eliminate this confusion, we have some rules of precedence, established at least as far back as the 1500s, called the "order of operations". A common technique for remembering the order of operations is the abbreviation (or, more properly, the "acronym") "PEMDAS", which is turned into the mnemonic phrase "Please Excuse My Dear Aunt Sally". Parentheses (simplify inside 'em) Exponents Multiplication and Division (from left to right) Addition and Subtraction (from left to right) When you have a bunch of operations of the same rank, you just operate from left to right. Content Continues Below Simplify 4 + 32. Simplify 4 + (2 + 1)2. Simplify 4 + [–1(–2 – 1)]2.

6 BASIC STATISTICAL TOOLS There are lies, damn lies, and statistics......(Anon.) 6.1 Introduction 6.2 Definitions 6.3 Basic Statistics 6.4 Statistical tests 6.1 Introduction In the preceding chapters basic elements for the proper execution of analytical work such as personnel, laboratory facilities, equipment, and reagents were discussed. It was stated before that making mistakes in analytical work is unavoidable. A multitude of different statistical tools is available, some of them simple, some complicated, and often very specific for certain purposes. Clearly, statistics are a tool, not an aim. 6.2 Definitions 6.2.1 Error 6.2.2 Accuracy 6.2.3 Precision 6.2.4 Bias Discussing Quality Control implies the use of several terms and concepts with a specific (and sometimes confusing) meaning. 6.2.1 Error Error is the collective noun for any departure of the result from the "true" value*. 1. * The "true" value of an attribute is by nature indeterminate and often has only a very relative meaning. 6.2.2 Accuracy 6.2.4 Bias 1.

Home - BrightStat Statistics made easy History of Normal Distribution History of the Normal Distribution Author(s) David M. Prerequisites Distributions, Central Tendency, Variability, Binomial Distribution In the chapter on probability, we saw that the binomial distribution could be used to solve problems such as "If a fair coin is flipped 100 times, what is the probability of getting 60 or more heads?" where x is the number of heads (60), N is the number of flips (100), and π is the probability of a head (0.5). Abraham de Moivre, an 18th century statistician and consultant to gamblers, was often called upon to make these lengthy computations. de Moivre noted that when the number of events (coin flips) increased, the shape of the binomial distribution approached a very smooth curve. Figure 1. de Moivre reasoned that if he could find a mathematical expression for this curve, he would be able to solve problems such as finding the probability of 60 or more heads out of 100 coin flips much more easily. Figure 2.

Conflict of interest The presence of a conflict of interest is independent of the occurrence of impropriety. Therefore, a conflict of interest can be discovered and voluntarily defused before any corruption occurs. A widely used definition is: "A conflict of interest is a set of circumstances that creates a risk that professional judgement or actions regarding a primary interest will be unduly influenced by a secondary interest Related to the practice of law[edit] Judicial disqualification, also referred to as recusal, refers to the act of abstaining from participation in an official action such as a court case/legal proceeding due to a conflict of interest of the presiding court official or administrative officer. In the legal profession, the duty of loyalty owed to a client prohibits an attorney (or a law firm) from representing any other party with interests adverse to those of a current client. Generally (unrelated to the practice of law)[edit] There often is confusion over these two situations.

salstat-statistics-package-2 - statistical package Para español [Home_es Página principal] Description Salstat2 is an statistical package written in python and designed for the end user It has a graphical user interface and also it is scriptable, It's multiplatform, It has a graphic system inherited from matplotlib, It allows you to use different libraries like numpy - for numerical calculations, it also lets you to interact with Microsoft Excel (R) by using a com client under windows(R) platform and finally you can create your own dialogs by using the interactive shell or the script panel. News 21-dec-2013: We will incorpore a frame to manage the pivot class since v2.2 alpha3 19-dec-2013: The easy dialog displays in a better way by using a flexgrid; Also we have reached 5900 downloads from different sources. 26-oct-2013: Added some video tutorials 26-oct-2013: We have reached 4699 downloads from different sources. 09-sep-2013:Salstat2 v2.2 alpha 2 is available here 08-Sep-2013:We have rached 3699 downloads! Statistical functions available

The T-Test « PreviousHomeNext » The t-test assesses whether the means of two groups are statistically different from each other. This analysis is appropriate whenever you want to compare the means of two groups, and especially appropriate as the analysis for the posttest-only two-group randomized experimental design. Figure 1 shows the distributions for the treated (blue) and control (green) groups in a study. What does it mean to say that the averages for two groups are statistically different? This leads us to a very important conclusion: when we are looking at the differences between scores for two groups, we have to judge the difference between their means relative to the spread or variability of their scores. The formula for the t-test is a ratio. The top part of the formula is easy to compute -- just find the difference between the means. Remember, that the variance is simply the square of the standard deviation. The final formula for the t-test is shown in Figure 5:

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