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ASK THE PROFESSOR FORUM

Course Documents

Chapter 1 - Intro

Chapter 2 - Methods for Describing Sets of Data

Chapter 3 - Probability

Chapter 4 - Discrete Random Variables

Chapter 5 - Normal Random Variables

Chapter 6 - Sampling Distributions

Chapter 7 - Confidence Intervals

Chapter 8 - Tests of Hypothesis: One Sample

Chapter 9 - Confidence Intervals and Hypothesis Tests: Two Samples

Sample Exam I: Chapters 1 & 2

Sample Exam II: Chapters 3 & 4

Sample Exam III: Chapters 5 & 6

Sample Exam IV: Chapters 7 & 8

Ask the Professor Forum

Hi professor,
I'm having some trouble with 9.7 / homework because I can't seem to figure out how to get SD difference. My calculator can't graph the work so I'm having trouble following your videos. On example 32. I can get the mean difference of 5.9 and the sample size of 10, but I cant figure out how to do Sd. (without looking into the video and seeing what you get.) . Is there any way you could possibly explain the process again to find the SD difference? Thanks.

Posted to STATS 2 on Thursday, October 17, 2013   Replies: 2


Professor Mcguckian
10/17/2013
4:40 PM EST

Hi Andrea,

On exams, you are usually provided the standard deviation of the differences for these types of questions. The reason is that it is time consuming to work them out by hand.  For the homework, I suggest that you just look at the answers briefly to get the standard deviation if you do not recall how to find it from Statistics I. 

If you want to learn how to do that calculation again, I have included that video in section 9.7. It is titled 'Review Concept (Standard Deviation)'. I have posted it below for you to view.

However, for the exam you will have all of the needed summary values provided to you.  

Hope that clears it up,

Professor McGuckian


.
10/17/2013
5:01 PM EST
Thank you, it helped a bunch!

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