63.27 % of fishes are gold fish
Solution:
Given that out of 49 fish, 31 are goldfish
To find: percent of gold fish
The percent of gold fish is calculated by dividing number of goldfish by total number of fish multiplied by 100
The percentage of gold fish is given by formula:

From given information,
total number of fish = 49
number of gold fish = 31
Substituting the values in formula, we get

Therefore, approximately 63.27 % of fishes are goldfish