## Symbols

There are a lot of different symbols used in statistics. There could also be symbols you have used before in another class, but mean something different in stats. To clear some confusion, I compiled a list of the more common symbols used in intro CSU stat courses.

NameSymbolDescription
Population Mean
A parameter, the population average.
Sample Mean
A statistic, the sample average.
Population Standard Deviation
A parameter, which measures the variability in the population.
Sample Standard Deviation
A statistic, which measures the variability in the sample
Sample Size
The number of observations in an experiment.
Pooled Standard Deviation
A weighted average of two groups standard deviations.
T Value
Can represent a test statistic when performing a t-test or the critical value when creating a CI.
Z Value
Can represent a z-score or a test statistic.
Sample Correlation
Measures the linear relationship between two variables.
Population Correlation
Measures the linear relationship between two variables.
Proportion
The number of "successes" over the total observations.
Null Hypothesis
The assumed hypothesis when performing a hypothesis test.
Alternative Hypothesis
The hypothesis we are trying to "disprove" in a hypothesis test.
Estimated Slope
The estimated slope in the line of best fit.
Estimated Y-Intercept
The estimated y-intercept in the line of best fit.
Population Slope
The theoretical slope in a linear regression model.
Population Y-Intercept
The theoretical y-intercept in a linear regression model.
Coefficient of Determination
The proportion of variability in the response that can be explained by the model.
Random Error
The random error term that is added in the theoretical linear regression model.
F Value
The test statistic used when performing ANOVA.