Covariance measures the linear relationship between two variables. The covariance is similar to the correlation between two variables, however, they differ in the following ways: Correlation coefficients are standardized. Thus, a perfect linear relationship results in a coefficient of 1. The correlation measures both the strength and direction of the linear relationship between two variables.
The Largest True Goldfish Ever Caught. The largest true goldfish on record was measured at 5lbs (2.27 kilograms) and was caught by a 16 year old schoolboy in the UK. This blown-up goldfish was evidently a pet before it ended up into a lake.
Goldfish are very large compared to many tropical fish species. Most fancy goldfish varieties grow up to 6 or 7 inches long (15 or 18 centimeters), while common and comet goldfish can grow to a foot long (30 centimeters) and even more. Though there are exceptions, tropical fish tend to stay small.