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  2. Design effect - Wikipedia

    en.wikipedia.org/wiki/Design_effect

    Where is the sample size, = / is the fraction of the sample from the population, () is the (squared) finite population correction (FPC), is the unbiassed sample variance, and (¯) is some estimator of the variance of the mean under the sampling design. The issue with the above formula is that it is extremely rare to be able to directly estimate ...

  3. Binomial distribution - Wikipedia

    en.wikipedia.org/wiki/Binomial_distribution

    The formula can be understood as ... The Bayes estimator is asymptotically efficient and as the sample size ... The addition of 0.5 is the continuity correction; the ...

  4. Pearson correlation coefficient - Wikipedia

    en.wikipedia.org/wiki/Pearson_correlation...

    Pearson's correlation coefficient, when applied to a population, is commonly represented by the Greek letter ρ (rho) and may be referred to as the population correlation coefficient or the population Pearson correlation coefficient. Given a pair of random variables (for example, Height and Weight), the formula for ρ[10] is [11] where.

  5. Ordinary least squares - Wikipedia

    en.wikipedia.org/wiki/Ordinary_least_squares

    It is common to assess the goodness-of-fit of the OLS regression by comparing how much the initial variation in the sample can be reduced by regressing onto X. The coefficient of determination R 2 is defined as a ratio of "explained" variance to the "total" variance of the dependent variable y , in the cases where the regression sum of squares ...

  6. Log-normal distribution - Wikipedia

    en.wikipedia.org/wiki/Log-normal_distribution

    Since the sample mean and variance are independent, and the sum of normally distributed variables is also normal, we get that: ^ + ˙ (+, + ()) Based on the above, standard confidence intervals for + can be constructed (using a Pivotal quantity) as: ^ + + And since confidence intervals are preserved for monotonic transformations, we get that

  7. Linear regression - Wikipedia

    en.wikipedia.org/wiki/Linear_regression

    t. e. In statistics, linear regression is a statistical model which estimates the linear relationship between a scalar response (dependent variable) and one or more explanatory variables (regressor or independent variable). The case of one explanatory variable is called simple linear regression; for more than one, the process is called multiple ...

  8. Normal distribution - Wikipedia

    en.wikipedia.org/wiki/Normal_distribution

    The simplest case of a normal distribution is known as the standard normal distribution or unit normal distribution. This is a special case when and , and it is described by this probability density function (or density): The variable has a mean of 0 and a variance and standard deviation of 1.

  9. Principal component analysis - Wikipedia

    en.wikipedia.org/wiki/Principal_component_analysis

    Principal component analysis (PCA) is a linear dimensionality reduction technique with applications in exploratory data analysis, visualization and data preprocessing.. The data is linearly transformed onto a new coordinate system such that the directions (principal components) capturing the largest variation in the data can be easily identified.