What are the characteristics of a graph that represent a proportional relationship?

How do i do this? i don’t understand

Suppose that prices of a gallon of milk at various stores in one town have a mean of $3.71 with a standard deviation of $0.10. using chebyshev's theorem, what is the minimum percentage of stores that sell a gallon of milk for between $3.41 and $4.01? round your answer to one decimal place.

Maria has $11 to buy fish for her aquarium. each goldfish costs $2. how many goldfish can she buy? do not include units in your answer