2.3.8]{\displaystyle {\begin{bmatrix}.7&.2\\.3&.8\end{bmatrix}}} (black).Stochastic matrices are square matrices whose rows are probability vectors, i.e., whose entries sum up to one. Stochastic matrices are used to define Markov chains with finitely many states.[70] A row of the stochastic matrix gives the probability distribution for the next position of some particle currently in the state that corresponds to the row. Properties of the Markov chain like absorbing states, i.e., states that any particle attains eventually, can be read off the eigenvectors of the transition matrices.[71]Statistics also makes use of matrices in many different forms.[72] Descriptive statistics is concerned with describing data sets, which can often be represented in matrix form, by reducing the amount of data. The covariance matrix encodes the mutual variance of several random variables.[73] Another technique using matrices are linear least squares, a method that approximates a finit