The mean is the sum of scores divided by the number of scores.
where is the number of scores.
Mode of a set of data is the value in the set that occurs most often.
The range of a set of data is the difference between the highest and lowest values in the set.
The variance of a sample measures how the conservations are spread around the mean.
The standard deviation is the square root of the average of the squared deviations from the mean (variance).
Categorical frequency distributions:
Categorical frequency distributions can be used for data that can be placed in specific categories, such as nominal- or ordinal-level data.
Central Limit Theorem:
As the sample size increases the sampling distribution of the sample mean approaches the normal distribution with mean and variance .
The exponential, binomial, and normal density functions:
The exponential, binomial and normal density functions are used to approximate statistical models and values.