notes 20 - Binomial Random Variable Submitted by gfj100 on...

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

View Full Document Right Arrow Icon
Binomial Random Variable Submitted by gfj100 on Wed, 11/11/2009 - 10:41 This is a specific type of discrete random variable. A binomial random variable counts how often a particular event occurs in a fixed number or tries. For a variable to be a binomial random variable, these conditions must be met: There are a fixed number of trials (a fixed sample size). On each trial, the even of interest either occurs or does not. The probability of occurrence (or not) is the same on each trial. Trials are independent of one another. Examples of binomial random variables: Number of correct guesses at 30 true-false questions when you randomly guess all answers Number of winning lottery tickets when you buy 10 tickets of the same kind Number of left-handers in a randomly selected sample of 100 unrelated people Notation n = number of trials (sample size) p = probability event of interest occurs on any one trial Example : For the guessing at true questions example above, n = 30 and p = .5 (chance of getting any one question right). Probabilities for binomial random variables The conditions for being a binomial variable lead to a somewhat complicated formula for finding
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

notes 20 - Binomial Random Variable Submitted by gfj100 on...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online