You are right about the domain.
1 people eat 3/8 pound of potato salad lets reoresent it：
x=3/8
Lets say n is the value of how many people ate with 7 people
7x=n
now substitute
7x=n
7(3/8)=n
21/8=n
n=2 5/8
Answer:
choice #3) similar by SSS
The corresponding sides do have the correct ratios.
