问题如下：
According to Chebyshev’s Inequality, what is the minimum percentage of the observations from a positive skewed distribution that will be within ±3.5 standard deviations of the mean?
选项：
A.8.2%.
B.71.43%.
C.91.8%.
解释：
C is correct
Chebyshev’s inequality states that regardless of the shape of the distribution, the percentage of the observations that lie within k standard deviations of the mean is at least 1-1/k2 for all k>1.
Applying Chebyshev’s inequality, 1 - [1 / (3.5)2] = 91.8%.
能不能麻烦老师讲下解题思路？
