CFA1, Quantitative Reading 8有关Chebyshev's Inequality的这首习题不懂，请老师与高手指点。
Over the past 240 months, an investor’s portfolio had a mean monthly return of 0.79%, with a standard deviation of monthly returns of 1.16%. According to Chebyshev’s inequality, the minimum number of the 240 monthly returns that fall into the range of −0.95% to 2.53% is closest to:
80.
107.
133.
