a family from a country with a low GDP has two brothers one is very tall and one is avrage height how could you explain the diffrence in their traits in terms of probility

In some developing nations the percentage of the animal protein from fish in the diet can be as high as 25 percent.  about 85% of fish caught is used for human consumption.  the remainder is converted into fishmeal and fish oil. 

The answer is 25.1  wont let me give a short have a nice day?