Statistics Basics > Statistics Symbols in Alphabetical Order

## Probability and Statistics Symbols

I’ve put these statistics symbols into quasi-alphabetical order, so that they are easy to find. When I say quasi-alphabetical, I mean that I have ordered them according to what they look like. For example, the Greek letter Beta (β) looks like the letter b, so you’ll find it in the **b** section. Same for the letter mu(μ), which looks like the letter u.cIf a statistics symbol doesn’t look like a letter, for example the “Greater than” symbol, >, you’ll find it at the very bottom under “miscellaneous.” Most items are clickable, taking you to an article that explains the statistics symbols in more depth.

## Statistics Symbols A to Z

**α**: significance level (type I error).

**b or b _{0}**: y intercept.

**b**: slope of a line (used in regression).

_{1}**β**: probability of a Type II error.

**1-β**: statistical power.

**BD or BPD**: binomial distribution.

**CI**: confidence interval.

**CLT**: Central Limit Theorem.

**d**: difference between paired data.

**df**: degrees of freedom.

**DPD**: discrete probability distribution.

**E**= margin of error.

**f**= frequency (i.e. how often something happens).

**f/n**= relative frequency.

**HT**= hypothesis test.

**H**= null hypothesis.

_{o}**H**: alternative hypothesis.

_{1}or H_{a}**IQR**= interquartile range.

**m**= slope of a line.

**M**: median.

**n**: sample size or number of trials in a binomial experiment.

**N**: population size.

**ND**: normal distribution.

**σ**: standard deviation.

**σx̅**: standard error of the mean.

**σp̂**: standard error of the proportion.

**p**: p-value, or probability of success in a binomial experiment, or population proportion.

**ρ**: correlation coefficient for a population.

**p̂**: sample proportion.

**P(A)**: probability of event A.

**P(AC) or P(not A)**: the probability that A doesn’t happen.

**P(B|A)**: the probability that event B occurs, given that event A occurs.

**Pk**: kth percentile. For example, P90 = 90th percentile.

**q**: probability of failure in a binomial or geometric distribution.

**Q1**: first quartile.

**Q3**: third quartile.

**r**: correlation coefficient of a sample.

**R**: coefficient of determination.

^{2}**s**: standard deviation of a sample.

**s.d or SD**: standard deviation.

**SEM**: standard error of the mean.

**SEP**: standard error of the proportion.

**t**: t-score.

**μ**mean.

**ν**: degrees of freedom.

**X**: a variable.

**Χ**: chi-square.

^{2}**x**: one data value.

**x̄**: mean of a sample.

**z**: z-score.

Miscellaneous Statistics Symbols

**~** has the distribution of (source).

**=** equal to.

**≈** almost equal to.

**> **greater than.

**< **less than.

**≠** not equal to.

**≤** less than or equal to.

**≥** greater than or equal to.

**Σ** Summation.

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