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 a spreadsheet developed by Microsoft but is by no means the first spreadsheet.   The very first spreadsheet was developed (or invented) by Dan Bricklin and Bob Fraâ¦nkston called VisiCalc. VisiCalc was a spreadsheet written to operate on the Apple II computer and was released in 1979.