Distributions
Student’s t-distribution
Student’s t-distribution is similar to a Gaussian distribution, but with heavier tails and shorter peaks.
TODO
Covariance And Correlation
Given two random variables $A$, $B$
- Mean
- Standard Deviation
1
- Standard Deviation indicates how spread out the data is from the mean.
- Covariance
1
- Covariance indicates **the Joint variability of $(A_i, B_i)$ pairs together.** If a single pair of $A_i$, $B_i$ are both positive, you will get a positive value. If one of them is positive, one of them is negative, you will get a negative value. Altogether, they could indicate how related $A$ and $B$ are.
- Correlation
\(\begin{gather*} corr(AB) = \frac{cov(AB)}{\sigma_A \sigma_B} \end{gather*}\) - Correlation is a standardized measure of “relatedness” between two random variables. It ranges from $[-1, 1]$. If $A=kB$ after mean normalization, then correlation will be a perfect 1
