Variance and Standard Deviation

1 / 4

# Variance and Standard Deviation - PowerPoint PPT Presentation

Variance and Standard Deviation. The Expected Value of a random variable gives the average value of the distribution The Standard Deviation shows how spread out the data is You can think of the standard deviation as “ the average distance of the data from the average ”

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

## PowerPoint Slideshow about 'Variance and Standard Deviation' - hateya

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Variance and Standard Deviation
• The Expected Value of a random variable gives the average value of the distribution
• The Standard Deviation shows how spread out the data is
• You can think of the standard deviation as “the average distance of the data from the average”
• The Variance is the square of the standard deviation
• Variance of discrete random variable
• Variance of continuous random variable
Variance, Dispersion

Variance. Dispersion

Text Example1. Suppose that we put 20 slips of paper, bearing the following numbers, into a box.

2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 6

Let X be number on a slip that is drawn, at random, from the box.

We put 20 slips of paper, bearing the following numbers, into a second box and let Y be the number on a slip that is drawn, at random, from that box.

1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7