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 $0.11. Using Chebyshev's theorem, what is the minimum percentage of stores that sell a gallon of milk for between $3.49 and $3.93? Round your answer to one decimal place.
a) 50.0%
b) 75.0%
c) 87.5%
d) 93.8%