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.
These guys are behind one of the greatest software breakthroughs of all time. Believe it or not, there was a time when our computers were incapable of functioning like a calculator, a time before Microsoft Excel. Enter Dan Bricklin and Bob Frankston, two men who wanted to see their calculators come to life. By creating VisiCalc, the first electronic spreadsheet, that's exactly what they did. Bricklin and Frankston would work at night because computer time was cheaper at night. They thought of it as a visual calculator and that is why they gave it the name VisiCalc.