{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# stats - Probability Mass Function A probability mass...

This preview shows pages 1–2. Sign up to view the full content.

Probability Mass Function A probability mass function (PMF) has the form: P(X = x) = some expression (usually containing x) that produces a probability of observing x = P(x) 1. P(x) is between 0 and 1 (inclusive) for each x 2. ∑P(x) = 1 Mean of Discrete Random Variables The mean of a discrete random variable represents the average value of the random variable if you were to observe this variable over an indefinite period of time. The mean of a discrete random variable is written as µ µ = ∑xP(x) Variance of Discrete Random Variables The variance of a discrete random variable, X, is a parameter describing the variation of the corresponding population. The symbol used is σ 2 σ 2 = ∑(x - µ) 2 • P(x) σ 2 = ∑x 2 P(x) - µ 2 Using Binomial Table A.1 to Determine Probabilities The binomial PMFs have been tabulated in Table A.1 for various values of n and p. If n = 4 and p = 0.3 and you wish to find the P(2) locate n = 4 and x = 2.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}