9. Bicycle Sales The probability that a bicycle shop sells 0, 1, 2, or 3 bicycles in a week is
3/8, 1/4, 1/4, and 1/8, respectively. Find the mean, variance, and standard deviation for the
distribution.
μ = E(X) = Σ [Χ* P(X) 1
σ² = Ε(Χ2) - μ² = Σ [Χ2 * P(X) 1 – μ²
σ = √σε
X
P(X)
X* P(X)
X2 * P(X)
Mean or expected value:
0
1
2
3
μ = Ε(Χ) = Σ[ X * P(X)] =
Variance:
Ε(Χ2) = ∑[ X2 * P(X)] =
σ² = Ε(Χ2) – μ² =
Standard deviation:
σ=