Answer:
Birds 
Gerbils 
Fish 
Hamsters 
Step-by-step explanation:
From the question we are told that:
Sales
Number of birds 
Number of gerbils 
Number of fish 
Number of hamsters
Generally the frequency for birds
is mathematically given b



Generally the frequency for Gerbils
is mathematically given b



Generally the frequency for fish
is mathematically given b



Generally the frequency for fish
is mathematically given b



For number 3 add all the numbers and divide how numbers you have
Study? I’m not sure what this is asking