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.
Lake Baikal is a huge lake in Siberia, Russia. It is the biggest fresh water reservoir in the world. The lake is near Irkutsk. Baikal is about 636 kilometres (395 mi) long. It is 20 to 80 kilometres (12 to 50 mi) wide. At its deepest point, it is 1,700 metres (5,600 ft) deep. With this depth it is the deepest lake on Earth. The lake is a UNESCO World Heritage Site. It holds about 20% of the world's unfrozen surface fresh water,