# MATH 225N Week 3 Discussion: Measures of Central Tendency and Variation

## MATH 225N Week 3 Discussion: Measures of Central Tendency and Variation

The way the answer was worked out for the example problem / exercise here was as follows:

We need the numerical labels for the seven “notches” or “tick marks” on the horizontal axis.

The middle of these seven notches or tick marks is x = 64.3  ( which is the mean here )

Then we do these calculations to find the other six numerical labels for the tick marks:

64.3  –  2.62  –  2.62  –  2.62  =  56.44

64.3  –  2.62  –  2.62  =  59.06

64.3  –  2.62  =  61.68

64.3  +  2.62  =  66.92

64.3  +  2.62  +  2.62  =  69.54

64.3  +  2.62  +  2.62  +  2.62  =  72.16

So that the labels ( and these are x values and NOT z values ) for the seven tick marks from left to right in the picture then are:

56.44      59.06      61.68      64.3      66.92      69.54      72.16

And so when answering the question having to do with the percent of women whose heights are between 59.06 inches and 64.3 inches, what we see from the picture in the last slide above is that 13.5% occurs between x = 59.06 and x = 61.68 and that another 34% occurs between x = 61.68 and x = 64.3, and so that therefore the total percentage occurring between x = 59.06 and x = 64.3 is 13.5% + 34%  =  47.5%

Thanks Friends and Be Well this Week 3 !!

🙂

Hi Friends and Greetings !!

As you have been finding out in your Weeks 1-3 Knewton Homework assignments, when there is a suspected outlier in the sample data, generally we shift towards preferring to use the median as a good measure of so-called central tendency.

On the other hand, if we don’t have any suspected outliers in the sample data, then we very often stick with preferring to use the mean as a good measure of central tendency.

When we say that we start to talk about and learn about distributions using shape, center, and spread, then what central tendency is – it is the fancy phrase or expression for “center.”

And the fancy phrase or expression for “spread” is “dispersion.”

Thanks Friends and I hope that you can conclude the Weeks 1-3 Knewton Homework assignments as quickly as possible and then try to dive into the Week 4 Knewton Homework assignments as quickly as is practical too !

Good Luck and Best Wishes Friends and THANK YOU for your hard work and attention !!

MATH 225N Week 3 Discussion: Measures of Central Tendency and Variation

Understanding descriptive statistics, their measures of center and their variability, helps form the foundation of statistical analysis. Descriptive statistics tell us how frequently an observation occurs, what is considered average, and how far data in our sample deviate from being average. With these statistics, we are able to provide a summary of characteristics from both large and small datasets. Measures of central tendency and variability provide valuable information on their own, and form the cornerstone of the quantitative structures that we build in our research studies.

### Required Resources

Read/review the following resources for this activity:

• OpenStax Textbook: Chapter 2
• Lesson
• Minimum of 1 scholarly source

### Initial Post Instructions

For this Discussion, you will examine central tendency and variability in terms of pulse rate.

Find and record the pulse rate of 10 different people where you work. Tell us a little about the population from which you drew your data. Describe your findings in terms of central tendency and variability.

What are your measures of central tendency (i.e., mean, median, and mode)? Which might be the better measure for central tendency and why?

What is the standard deviation of your data? How variable are the data (range)?

Are there any outliers? Investigate possible reasons for these outliers, and things that might limit them if further study were to be carried out.

What are some variables that should be considered in discussing your measures of central tendency and variation? Is there any skewness in your measured data?

How would you describe this data (i.e. what insights did you gain from this data)?

### Follow-Up Post Instructions

Respond to at least two peers or one peer and the instructor. Further the dialogue by providing more information and clarification.

### Writing Requirements

• Minimum of 3 posts (1 initial & 2 follow-up)
• APA format for in-text citations and list of references

Course Outcomes (CO): 4

Due Date for Initial Post: By 11:59 p.m. MT on Wednesday

Due Date for Follow-Up Posts: By 11:59 p.m. MT on Sunday

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For grading purposes, this particular discussion posting area runs from Sunday Jan 17 through Sunday Jan 24, inclusively.

We explore the so-called Normal Distributions this Week. This includes normal probability distributions, the standard normal distribution, the standard normal distribution Table, the concept of continuous distributions, sampling distributions, and the Central Limit Theorem.

Please don’t forget to use an “outside” resource as part of the content and documentation for your first Post – the Post which is due on or before Wednesday of the Week – the Post where you make the most major contribution to the Weekly discussion posting area and attempt to address the discussion prompts / cues for the Week. It could possibly include a web site that you discovered on the internet at large, so long as the web site is relevant and substantial and does not violate the Chamberlain University policy for prohibited web sites, and so forth. It could possibly include references / resources that you discover through making use of the online Chamberlain University Library ( please click Resources along the left and then click Library to discover the link to the Chamberlain University online Library

Check out the link below for some information about the so-called Standard Normal Distribution.  After that page comes up also click on the normal distribution link from that page to see some more useful and relevant information for our Week 3 concerns and COs.

This is one kind of an example of using an “outside” source / resource to add to what is revealed in our Weekly Lesson in Modules and in our Weekly text book reading.

Please don’t forget to look over the Graded Discussion Posting Rubric each Week to be certain that you are meeting all of the Frequency requirements as well as all of the Quality requirements for graded discussion posting each Week.

If you have any questions about anything, please do not hesitate to post in the Q & A Forum discussion posting area or to send me a direct e-mail message to  [email protected]

Thanks Friends and Good Luck !  Work hard and learn a lot !!

Sincerely,  Mr. Smith     Chamberlain University     Math, Statistics, and Quantitative Research

I want to please make a couple of things clear here for uniformity and clarity and consistency.

Please record the pulse rate for one minute / 60 seconds per person.

If it is typical that you just “take” the pulse for 15 seconds and then therefore multiply it by 4 then so be it – you all would know much much better than me how things are done…

But PLEASE everyone use a rate for a 60 seconds / one minute time period so that we all can look at each other’s numbers ( data values ) and means and medians and sample standard deviations and so forth and all be on the same page and in the same frame of mind and have the same reference points and point of view and thinking and all that when looking at each other’s numbers and results.

ALSO I want to make it clear that I am going to make a few Posts with an “Example” of these Week 3 questions and concerns but that my “example” will involve a sample size of n = 30

But you all please stick to the assignment instructions / directions and use a sample size of n = 10 please.

Thanks and Best Wishes !  Have fun with this assignment !!  Use your Week 3 spread sheet( s ) on this assignment as much as you possibly can !  Even attach copies of your Week 3 spread sheet( s ) to your Posts with your actual 10 pieces of data filled in and so forth !  Enjoy and Learn Friends !!!

Don’t forget the lab turn in assignment in Week 3 !!!!

We have Knewton Quizzes in Weeks 2 4 6 and lab turn in assignments in Weeks 3 5 7 .

Good Luck and Best Wishes Friends !!

Hi XXXXX and Greetings and thanks for your Post here !  I really appreciate it !!    🙂

It looks like you might have had some trouble trying to get a graphic / image into your Post and so I wanted to try it out for myself and see if I could get it to work.      😉

The process involved a couple of unexpected steps for me, so I will share as much as I can here to hopefully help Folks who might want to place something like this in a Post during Weeks X-X .    😉

XXXXX gave some great instructions on doing this kind of thing too, but I have a variation on a few of the steps that she performed.    😉

First, before copying and pasting the Excel output to an open blank Word document, I had to go through the very irritating step of giving all the cells to be copied and pasted a sort of light background – that orangy peachy color that you see.

Otherwise when I created my jpg / jpeg most of the cells were dark black and not readable so to speak.

Next in Excel I highlighted the cells to be copied and then did contol c

Then in a blank Word document I used the mouse and clicked but had to be careful about which Paste option that I used – I had to use Paste as a picture, which was one of the last options available to me from left to right.