Statistics

Statistics is the study of the collection, organization, analysis and interpretation of data. It deals all aspects of this, including the planning

of data collection in terms of the design of surveys and experiments.

Descriptive statistics summarize the population data by describing what was observed in the sample numerically or

graphically. Numerical descriptors include mean and standard deviation for continuos data types (like heights or weights), while frequency and percentage are more useful in terms of describing

categorial data (like race).

In statistics, mean has two related meanings: the arithmetic mean (and is distinguished from the geometric mean or harmonic mean). the expected value of a random variable , which is also called the population mean.

There are other statistical measures that should not be confused with averages – including ‘median’ and ‘mode’. Other simple statistical analyses use measures of spread, such as range, interquartile range, or standard deviation. For a real-valued

random variable X, the mean is the expectation of X. Note that not every probability distribution has a defined mean (or

variance).

Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows

how much variation or “dispersion” exists from the average (mean, or expected value). A low standard deviation

indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data points are spread out over a large range of values.

ESEGUITO DA

MANUEL DE CHIARA VALERIE DE CHIARA FRANCESCO FORTUNATO ANTONIO VERNI

FINE