NO.PZ2024120401000059
问题如下：
The probability distribution of a discrete random variable f(X=xᵢ) satisfies:
选项：
A.
f(X=xᵢ) = P(X = xᵢ), i = 1,2,3... and f(X) = 0, x ≠ xᵢ, 0 ≤ f(xᵢ) ≤ 1, ∑f(xᵢ) = 1
B.
f(X=xᵢ) = P(X > xᵢ), i = 1,2,3... and f(X) = 0, x ≠ xᵢ, 0 ≤ f(xᵢ) ≤ 1, ∑f(xᵢ) = 1
C. f(X=xᵢ) = P(X < xᵢ), i = 1,2,3... and f(X) = 0, x ≠ xᵢ, 0 ≤ f(xᵢ) ≤ 1, ∑f(xᵢ) = 1
D.f(X=xᵢ) = P(X ≤ xᵢ), i = 1,2,3... and f(X) = 0, x ≠ xᵢ, 0 ≤ f(xᵢ) ≤ 1, ∑f(xᵢ) = 1
解释：
A选项的f(x)=0是什么意思，还有后面的，没有明白