Given a normal distribution of data, we know from the Empirical Rule that in between 2 standard deviations from the mean (i.e. xbar - 2s..to..xbar + 2s) there lies about 95% of all the data.
Calculate and show the percentage of data from xbar - 2s..to..xbar + 2s using Chebyshev's theorem.
Now, if I told you that a certain data set has about 87% of the data between the data points xbar + 2s, how would you reconcile this percentage against what is known for both the Empirical Rule and what you calculated above with Chebyshev's theorem?