In statistical theory, covariance is a measure of how much two random variables change together. In other words, covariance is a measure of the strength of the correlation between two random variables. Also, it can be considered as a generalization of the concept of variance of two random variables.
Facts & Figures. Lake Baikal is the largest freshwater lake by volume (23,600km3), containing 20% of the world's fresh water. At 1,637m, it is the deepest freshwater lake in the world; the average depth is 758m. It is 636km long and 81km wide; the surface area is 31,494km2. The lake is estimated to be 25 million years old, making it one of the most ancient lakes in geological history.
The World's Deepest Lake. Lake Baikal in southern Russia is the world's deepest lake. It is an estimated 5,387 feet deep (1,642 meters), and its bottom is approximately 3,893 feet (1,187 meters) below sea level. Lake Baikal is also the world's largest freshwater lake in terms of volume.