Answer:
The minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17 is of 75%.
Step-by-step explanation:
Chebyshev Theorem
The Chebyshev Theorem can also be applied to non-normal distribution. It states that:
At least 75% of the measures are within 2 standard deviations of the mean.
At least 89% of the measures are within 3 standard deviations of the mean.
An in general terms, the percentage of measures within k standard deviations of the mean is given by .
In this question:
We have a mean of $3.91 and a standard deviation of $0.13.
Using Chebyshev's Theorem, what is the minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17?
3.65 = 3.91 - 2*0.13
4.17 = 3.91 + 2*0.13
Within 2 standard deviations of the mean, so, by the Chebyshev's Theorem, the minimum percentage of stores that sell a gallon of milk for between $3.65 and $4.17 is of 75%.