My Math Forum  

Go Back   My Math Forum > High School Math Forum > Probability and Statistics

Probability and Statistics Basic Probability and Statistics Math Forum


Reply
 
LinkBack Thread Tools Display Modes
May 1st, 2015, 11:12 PM   #1
Member
 
Joined: Dec 2012

Posts: 38
Thanks: 0

Quick Statistics Question

Hey all - haven't been back for a while. Fiancé is taking Statistics in Justice Studies class and we are reading the book but cannot understand for the life of me why the Summation (E) sign has no explanation on how to solve. We understand everything else but can't get to the Summation formula. I know that Summation is X1+X2...XN but it doesn't work in this case as they have the XD pieces involved.

Any idea on how they got to the answer 2.12 number there at the bottom?

Screenshot attached below.

http://mymathforum.com/attachment.ph...1&d=1430550722
Attached Images
File Type: jpg FullSizeRender.jpg (89.1 KB, 5 views)
Bosanac is offline  
 
May 2nd, 2015, 02:09 AM   #2
Senior Member
 
Joined: Jan 2012
From: Erewhon

Posts: 245
Thanks: 112

Quote:
Originally Posted by Bosanac View Post
Hey all - haven't been back for a while. Fiancé is taking Statistics in Justice Studies class and we are reading the book but cannot understand for the life of me why the Summation (E) sign has no explanation on how to solve. We understand everything else but can't get to the Summation formula. I know that Summation is X1+X2...XN but it doesn't work in this case as they have the XD pieces involved.

Any idea on how they got to the answer 2.12 number there at the bottom?

Screenshot attached below.

http://mymathforum.com/attachment.ph...1&d=1430550722
The $2.12$ is the sum of the values in the column of $x_D$ that is $0.83+1.96-0.07-0.14-0.46=2.12$ so the arithmetic mean of the $x_D$s is this sum divided by the number of items $\bar{x}_D=2.12/5=0.424$

CB
CaptainBlack is offline  
May 2nd, 2015, 02:29 PM   #3
Member
 
Joined: Dec 2012

Posts: 38
Thanks: 0

Thank so much Captain... that makes so much sense now I can do the rest of the problems... I just needed that formula.

Also, struggling a bit with the last problem of the practice... Final exam is coming up so I am taking the practice exam and it is not making much sense to me.

Any idea on how to put this into a formula so I can solve?

Oh and these are the five steps it gives me...

Step 1. State the Null and Alternative Hypotheses
Step 2. Identify the Distribution and Compute the Degree of Freedom
Step 3. Identify the Critical Value and State the Decision Rule
Step 4. Calculate the Obtained Value of the Test Statistic
Step 5. Make A Decision About the Null and State the Substantive Conclusion
Attached Images
File Type: jpg Full Render.jpg (110.9 KB, 1 views)
Bosanac is offline  
Reply

  My Math Forum > High School Math Forum > Probability and Statistics

Tags
question, quick, statistics



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quick question. hyperbola Pre-Calculus 7 February 20th, 2015 03:29 AM
Very quick question Timk Algebra 3 March 27th, 2012 10:31 PM
Log question (need help quick) schLoL Algebra 5 April 26th, 2011 03:36 PM
help?? quick question mathhelp123 Calculus 1 October 30th, 2009 02:21 PM
quick hw question axelle Economics 1 May 17th, 2008 10:44 PM





Copyright © 2019 My Math Forum. All rights reserved.