Statistical Symbols
Here are given below statistics symbol’s, with names meanings-
<td”>variancevariance of population values
| Symbol | Symbol Name | Meaning |
| ∑ | summation | summation – sum of all values in range of series |
| ∑∑ | double summation | double summation |
| μ | population mean | mean of population values |
| E(X) | expectation value | expected value of random variable X |
| E(X | Y) | conditional expectation | expected value of random variable X given Y |
| var(X) | variance | variance of random variable X |
| σ2 | ||
| s 2 | sample variance | population samples variance estimator |
| s | sample standard deviation | population samples standard deviation estimator |
| std(X) | standard deviation | standard deviation of random variable X |
| σX | standard deviation | standard deviation value of random variable X |
| Mo | mode | value that occurs most frequently in population |
| MR | mid-range | MR = (xmax + xmin) / 2 |
| Md | sample median | half the population is below this value |
| Q1 | lower / first quartile | 25% of population are below this value |
| Q2 | median / second quartile | 50% of population are below this value = median of samples |
| Q3 | upper / third quartile | 75% of population are below this value |
| _ X |
sample mean | average / arithmetic mean |
| zx | standard score | |
| X ~ | distribution of X | distribution of random variable X |
| N(μ,σ2) | normal distribution | gaussian distribution |
| gamma(c, λ) | gamma distribution | |
| exp(λ) | exponential distribution | |
| U(a,b) | uniform distribution | equal probability in range a,b |
| Poisson(λ) | Poisson distribution | |