1. The problem statement, all variables and given/known data 2. Relevant equations P (|Y - μ| < kσ) ≥ 1 - Var(Y)/(k2σ2) = 1 - 1/k2 ?? 3. The attempt at a solution using the equation above 1 - 1/k2 = .9 .1 = 1/k2 k2 = 10 k = √10 = 3.162 k = number of standard deviations. After this I don't know where to go. I don't have a solid understanding of Chebyshev's inequality either.