Discrete Random Variables Quiz

• A function that gives the probability that a discrete random variable is less than or equal to some value
• A function that gives the probability that a discrete random variable is exactly equal to some value (correct)
• A function that gives the probability that a discrete random variable is greater than or equal to some value
• A function that gives the probability that a discrete random variable is between two values

• $E(X) = \\sum_{i} x_iP(X=x_i)$ (correct)
• $E(X) = \\frac{1}{n}\\sum_{i=1}^{n} x_i$
• $E(X) = \\frac{1}{n}\\sum_{i=1}^{n} P(X=x_i)$
• $E(X) = \\sum_{i} P(X=x_i)$

• The range of the random variable's values
• The average of the squared differences from the mean (correct)
• The average of the absolute differences from the mean
• The sum of the squared differences from the mean