Probability Distributions Ch 4

Probability Distributions Ch 4 - Random variable follows a...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Probability Distributions Random variable – variable assigned one and only one numerical value for each outcome of an experiment Discrete – Ex. Roll 1 fair die; Payout of $1 if roll is a 1, $0 if roll is 2,3,4,5, and -$1 if roll is a 6 Continuous – Ex. Weight of chips in a bag of potato chips measured in oz.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Probability distrib applies to the population E(X) = mu = (long run average) V(X) = sigma squared = (variance = std dev squared)
Background image of page 2
Examples Rolling fair die with payouts as given Roulette wheel and bet $2 on black
Background image of page 3

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

View Full DocumentRight Arrow Icon
Empirical Rule If distribution is approx bell-shaped, then 68% of outcomes 95% of outcomes 99.7% of outcomes
Background image of page 4
Binomial Distribution
Background image of page 5

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

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

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

View Full DocumentRight Arrow Icon
Background image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Random variable follows a binomial distrib if 1. Perform n identical trials 2. Only two possible outcomes (S,F) 3. P(S) is constant on each trial 4. Trials are independent 5. Random variable of interest is number of successes (S) on the n trials Binomial Calculations Binomial formula for n trials, P(S)=p, and X is the random variable for number of Ss P(X=x) = Where X= 0,1,2,3,,n Table for Cumulative Binomial Table II, textbook p.875-878 For certain values of n and p, table gives the P(X less than or equal to x) Example: n=6, p=.7 then P(X 4) =0.580 What is P(X=4)? Practice Problem Chapter 4 # 44, p. 216...
View Full Document

This note was uploaded on 03/16/2009 for the course ECN 221 taught by Professor Roberts during the Spring '07 term at ASU.

Page1 / 8

Probability Distributions Ch 4 - Random variable follows a...

This preview shows document pages 1 - 8. Sign up to view the full document.

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