GUATEMALA CITY - Torrential rains brought by the first tropical storm of the 2010 season pounded Central America and southern Mexico, triggering deadly landslides. The death toll stood at 15 Sunday but authorities said the number could rise.
Archimedes proved the formula for the area of a circle (A = Ï r 2, where r is the radius of the circle) and showed that the value of Ï lay between 3 + 1/7 (approximately 3.1429) and 3 + 10/71 (approximately 3.1408).
The previous two examples have suggested how we should define the measure formally. In short, the coefficient of determination or r-squared value, denoted r 2, is the regression sum of squares divided by the total sum of squares. Alternatively, as demonstrated in this, since SSTO = SSR + SSE, the quantity r 2 also equals one minus the ratio of the error sum of squares to the total sum of squares: