When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. 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 μ = 0 {\textstyle \mu =0} and σ 2 = 1 {\textstyle \sigma ^{2}=1} , and it is described by this probability density function (or density): φ ( z ) = e − z 2 2 2 π . {\displaystyle \varphi (z ...

  3. Standard deviation - Wikipedia

    en.wikipedia.org/wiki/Standard_deviation

    If a data distribution is approximately normal then about 68 percent of the data values are within one standard deviation of the mean (mathematically, μ ± σ, where μ is the arithmetic mean), about 95 percent are within two standard deviations (μ ± 2σ), and about 99.7 percent lie within three standard deviations (μ ± 3σ).

  4. Standard normal table - Wikipedia

    en.wikipedia.org/wiki/Standard_normal_table

    Download as PDF; Printable version; ... The standard normal distribution, represented by Z, is the normal distribution having a mean of 0 and a standard deviation of 1.

  5. Log-normal distribution - Wikipedia

    en.wikipedia.org/wiki/Log-normal_distribution

    A closed-form formula for the ... the cumulative distribution function, the pdf and the ... follows a log-normal distribution with standard deviation ...

  6. Multivariate normal distribution - Wikipedia

    en.wikipedia.org/wiki/Multivariate_normal...

    In one dimension the probability of finding a sample of the normal distribution in the interval is approximately 68.27%, but in higher dimensions the probability of finding a sample in the region of the standard deviation ellipse is lower.

  7. 68–95–99.7 rule - Wikipedia

    en.wikipedia.org/wiki/68–95–99.7_rule

    Diagram showing the cumulative distribution function for the normal distribution with mean (μ) 0 and variance (σ 2) 1. These numerical values "68%, 95%, 99.7%" come from the cumulative distribution function of the normal distribution. The prediction interval for any standard score z corresponds numerically to (1 − (1 − Φ μ,σ 2 (z)) · 2).

  8. Sum of normally distributed random variables - Wikipedia

    en.wikipedia.org/wiki/Sum_of_normally...

    This means that the sum of two independent normally distributed random variables is normal, with its mean being the sum of the two means, and its variance being the sum of the two variances (i.e., the square of the standard deviation is the sum of the squares of the standard deviations). [1]

  9. Rayleigh distribution - Wikipedia

    en.wikipedia.org/wiki/Rayleigh_distribution

    PDF / CDF / Quantile (;) ... , where c 4 is the correction factor used to unbias estimates of standard deviation for normal ... The half-normal distribution is the ...