Download presentation

Presentation is loading. Please wait.

Published byBrooklynn Shackford Modified over 2 years ago

1
Means and Variances of RV 7.2

2
Example # of BoysP(X) 0.0625 1.25 2.375 3.25 4.0625 Find the expected value, or mean, of the probability distribution above:

3
Mean of a Discrete RV Also called the expected value, what we would expect if we took many trials Suppose X is a discrete RV whose distribution is: Value of Xx 1 x 2 x 3 …x k Probabilityp 1 p 2 p 3 …p k The mean of X is found by: – µ x = E(X) =

4
Example cont. # of BoysP(X)Dev (x - µ)Dev (x - µ) 2 0.0625 1.25 2.375 3.25 4.0625 Find variance (σ 2 ) of the probability distribution above. note: variance is the expected value of the squared deviations from the mean): Find the standard deviation (σ) note: variance is standard deviation squared:

5
Variance of a Discrete RV Suppose X is a discrete rv whose distribution is: Value of Xx 1 x 2 x 3 …x k Probabilityp 1 p 2 p 3 …p k And that is the mean of X. The variance of X is: The standard deviation σ x of X is the square root of the variance.

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on ten sikh gurus Download ppt on separation of substances Ppt on life history of mahatma gandhi Ppt on amplitude shift keying modulation Ppt on tata trucks Ppt on series and parallel circuits battery Ppt on credit policy document Ppt on channels of distribution examples Ppt on magnetic field lines Ppt on disaster management project