(1+2x/x²+1) : (1+2/x-1)

I'm confused on this could anyone me and show me what i need to do to solve it.

Asequence is a function whose is the set of natural numbers

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.