in statistics, summation denoted by upper case sigma, is used to find the sum of a series of observation in a particular variable.
Generally, progressive summation is the process of obtaining a cumulative sum at any time by adding together all prior occurrences.
Descriptive statistics is a summary of data. Inferential statistics try to reach conclusion that extend beyond the immediate data alone.
statistic is singular and statistic is plural
Statistics is a general field of numeric quantities and what they represent. For example, a statistic may be inferential or descriptive. Inferential statistics are special kinds of statistics that...
statistics means numerical facts systematically collected and statistic means, scientific matter or technique of statistical analysis.