# Types of Statistical Tests

Measures of Central Tendency A measure of central tendency is a single value that attempts to describe a set of data by identifying the central position within that set of data. As such, measures of central tendency are sometimes called measures of central location. They are also classed as summary statistics. The mean (often called the average) is most likely the measure of central tendency that you are most familiar with, but there are others, such as the median and the mode.

Measures of Dispersion or Variation The standard deviation, s, is the square root of the variance. What the formula means: (1) x r - m means take each value in turn and subtract the mean from each value.

Measures of Frequency: * Count, Percent, Frequency The relative frequency (or empirical probability) of an event is the absolute frequency normalized by the total number of events: = = ∑. The values of for all events can be plotted to produce a frequency distribution.

Measures of Position How to Determine Measures of Position ... Both percentiles and quartiles are statistical measures of position; ... a student who gets a test score in the 90th ...