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Filename: controllers/formulas.php
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Terms | Notation | Formula |
Population mean | µ | ∑x/ N |
Population variance | σ^2 | ∑(x-µ)^2/N |
Population standard deviation | σ | √[∑(x-µ)^2/N] |
Sample mean | x? | ∑x/n |
Sample variance | s^2 | ∑(x - x?) ^2/ n-1 |
Sample standard deviation | s | √[∑(x - x?) ^2/ n-1] |
Mean absolute deviation | MAD | ∑|x - µ| / N |
Range | Range | Largest value – Smallest value |
Midrange | Midrange | (Largest value – Smallest value) / 2 |
Interquartile range | IQR | Q3- Q1 |
Coefficient of variation | CV | σ/µ (100) |
Discrete probability Mean Standard deviation |
µ σ |
∑ x P(x) √[∑x^2 P(x) - µ^2] |
Binomial probability Mean Standard deviation |
P(x) µ σ |
nCxp^x q^(n-x) np √npq |
Poisson probability Mean Variance Standard deviation |
P(x) µ σ^2 σ |
?^x e^*(-x) / x! ? ? √? |
Z score | z | (x- µ) / σ |
Correlation coefficient | r | SSxy/ √(SSxx * SSyy) |
Simple regression | y^ = a+ bx |