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).
1 The R-squared value, denoted by R, is the square of the correlation. 2  It measures the proportion of variation in the dependent variable that can be attributed to the independent variable. 3  The R-squared value R is always between 0 and 1 inclusive. 4  Perfect positive linear association.