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.
Codenamed Odyssey, Excel is a software program from Microsoft that is part of the Microsoft Office suite of software programs. Developed by Microsoft and first released on September 30, 1985, Excel is capable of creating and editing spreadsheets that are saved with a .xls or .xlsx file extension.