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GLD223
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Nearly every natural relationship between variables (within some arbitrary range) either looks linear, quadratic, exponential, sinusoidal or gaussian. Change the scales of the x and y axes an you can get a 'convincing fit' (good enough, often to convince a jury).GLD223 said:
A Gaussian distribution, also known as a normal distribution, is a continuous probability distribution characterized by its bell-shaped curve. It is defined by two parameters: the mean (average) and the standard deviation (spread or width). Many natural phenomena and measurement errors tend to follow this distribution.
Many datasets appear to follow a Gaussian distribution due to the Central Limit Theorem, which states that the sum of a large number of independent, identically distributed variables will tend to be normally distributed, regardless of the original distribution of the variables. This is why Gaussian distributions are commonly observed in various fields such as physics, biology, and social sciences.
To determine if your data follows a Gaussian distribution, you can use statistical tests such as the Shapiro-Wilk test, Anderson-Darling test, or Kolmogorov-Smirnov test. Additionally, visual methods like Q-Q plots (quantile-quantile plots) can help you assess normality by comparing the quantiles of your data against the quantiles of a normal distribution.
If your data does not follow a Gaussian distribution, you can consider data transformations (such as log, square root, or Box-Cox transformations) to make it more normal. Alternatively, you can use non-parametric statistical methods that do not assume normality, such as the Mann-Whitney U test or the Kruskal-Wallis test.
While the basic shape of a Gaussian distribution is always bell-shaped, its specific appearance can vary based on the mean and standard deviation. A higher standard deviation results in a wider and flatter curve, while a lower standard deviation results in a narrower and taller curve. The mean shifts the center of the distribution along the horizontal axis.