Normal distribution PDF formula
Normal distribution PDF formula
The normal distribution, also known as Gaussian distribution, is a fundamental concept in probability theory and statistics. Its probability density function (PDF) is crucial for understanding the distribution of continuous data.
The formula for the normal distribution PDF is given by:
f(x) = (1 / (σ√(2π))) * exp(-((x - μ)² / (2σ²)))
In this formula, μ represents the mean of the distribution, σ represents the standard deviation, and exp denotes the exponential function. The constant (1 / (σ√(2π))) is the normalization factor that ensures the total area under the curve equals 1.
Understanding the normal distribution PDF is essential for various applications in statistics, such as hypothesis testing, confidence intervals, and data analysis. It helps in determining probabilities and making inferences about population parameters based on sample data.
Example
For a normal distribution with a mean (μ) of 50 and a standard deviation (σ) of 10, the PDF at x = 60 is calculated as follows: f(60) = (1 / (10√(2π))) * exp(-((60 - 50)² / (2 * 10²))) = (1 / (10√(2π))) * exp(-((10)² / (200))) = (1 / (10√(2π))) * exp(-0.5) ≈ 0.024
The normal distribution PDF formula is fundamental in statistics for calculating probabilities and making inferences about population parameters.
Expected value
Expected value formula: E[X] = Σ [x * P(x)]
Poisson distribution
Poisson distribution formula: P(k; λ) = (λ^k * e^(-λ)) / k!
Batch normalization
Batch normalization formula: Y = (X - μ) / σ * γ + β
Softmax function
Softmax converts real numbers into a probability distribution
Pearson correlation coefficient
Pearson correlation coefficient formula: r = Σ[(xi - x̄)(yi - ȳ)] / [√(Σ(xi - x̄)²) * √(Σ(yi - ȳ)²)]
Logistic regression
Logistic regression probability formula: P(Y=1) = 1 / (1 + exp(-z))
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