Chebyshev's Theorem states that withing 2 standard deviations (regardless of the mean) that 95% of data is contained. There is also a theorem that states the minimum % of data that will lie between 2 standard deviations.

Question

Chebyshev's Theorem states that regardless of the distribution at least (100(k^2 - 1)) / (k^2) % of the data is guarunteed to lie within k standard deviations of the mean.
a) What is the minimum % of the data that Chebyshev's Theorem guaruntees will lie within 2 standard deviations of the mean for any distribution?
b) Verify the prediction in a) for the data 0, 9, 9.