The direction of a correlation is either positive or negative. In a negative correlation, the variables move in inverse, or opposite, directions. In other words, as one variable increases, the other variable decreases. For example, there is a negative correlation between self-esteem and depression. In other words, the higher your self-esteem, the lower your feelings of depression.
Excel Communications was founded in 1988 by Dallas entrepreneur Kenny Troutt as a long distance reseller in the US telecom sector at the birth of telecom deregulation.
Excel is the very popular file format created by Microsoft. Although it is not an opened file format, Java applications can still read and write Excel files using the Apache POI-the Java API for Microsoft Documents, because the development team uses reverse-engineering to understand the Excel file format.