Calculating z scores

Janet,
What is the sample size that led you to the sample mean of 3 and standard deviation of 1? If you have around 30 observations, then your Z would be around 20. But I assume you don’t have a measure of the entire population, so the T statistic would be more appropriate to use. In either case, the result would be around Z or T = 20. But you need the mean, standard deviation, and sample size to know for sure.
My guess you running around 3-4 sigma depending on your answers to the questions above.
Regards,
Dr. Scott
 
 
 

Dr. Scott,I am looking to replicate the famous experiment from the Juran on
Quality tapes. He talked of trying different liquors mixed with water to
find what was making him drunk.What should the sample size be for this?

Should I use randomization when setting this up?

Hey Blessed,
So, if my goal is to spread a little knowledge, learn a little now and then, have some fun, exchange some thoughts with really smart people, do some offline networking with some really talented professionals and cause some trouble when so inclined, does that make me unblessed?  Might be revealing if some of the more frequent posters shared their thoughts as to why they post on this site.

Blessed thy be,
Dr. Juran said it, I only quoted him. So bless him. And, by the way, I do feel blessed. I have received opportunities that 30 years ago I would not have even imagined receiving. But, by the grace of God, I am able to accomplish more than I ever thought I could.
I truly hope God blesses you in such a way as well.
Also, please check your grammar and spelling before posting again.
Dr. Scott

Darth,
All I can say is “Right On”! Seems our purpose is the same afterall.
Cordially,
Dr. Scott

I am your school :-).
I am starting to enjoy ostensibly knowledgeable people like you. You have nothing to contribute, nothing to discuss, and nothing to deliberate. You only offer insults. That is a very bad flaw. Some would call that psychopath: a mentally ill or unstable person; especially: a person affected with antisocial personality disorder.
 
I only wish the antisocial part applied to you, so you would stop bringing social issues to this professional forum which would mean you would no longer be here.
 
Why don’t you tell me what the Z is without historical data? Are you even able to do so, or would you rather continue to be a non-contributor?
Dr. Scott

z score, t-score … that is such baby stuff that I even wonder why you bother. Every introductory textbook including Wilkipedia has the answer. Do you really think that your rule of thumb of 30 is a great contribution? BTW, I only respond to your silly tirades when you get totally out of control, like in your Juran quote (Juran was the only non-statistician who had to rub into everybody’s face he was one … you’re awfully similar to him). Other than that, I couldn’t care less about your opinions and your “famous” contributions. … and “fruitcake”, “idiot”, and your absolutely out of control ranting about “Jack Daniels” that’s worthy a professional aka “Dr.” aka “consultant” … any other titles you can randomly throw around to make you feel better about yourself? As for my contributions, YOU don’t worry have to worry about them. I find it embarrasing to sign them with “Dr. XYZ” in an environment that is dedicated to professionals who for the most part are still working on their academic education. Have a good night. You really need one to clear your mind :-))))).
P.S. A “Z” is the last letter of the alphabet in capital letter. If you want to know what the formula for a z-value is (population/sample) and how to use it in its various practical applications, please use the google search function. I’m not your statistics mentor.

Ok Blessed, I will indulge your fantasy to be me one last time. Read my BOLD below in response to your post.
z score, t-score … that is such baby stuff that I even wonder why you bother.
Because Z represents a population and T represents a sample. If it so text book, why didn’t you know it? Is it because you can’t read? I can help you with that as well. Sorry for my error in not capitalizing Z and T in the post you referenced.
Every introductory textbook including Wilkipedia has the answer. Do you really think that your rule of thumb of 30 is a great contribution?
The rule of 30 isn’t my contribution. I wish I could say it was, but that belongs to others such as Deming, Shewhart, and Juran. But it works. If you had any real experience at all, then you would know that.
BTW, I only respond to your silly tirades when you get totally out of control, like in your Juran quote (Juran was the only non-statistician who had to rub into everybody’s face he was one … you’re awfully similar to him).
I will take your comparison to Dr. Juran as a compliment. And yes he was an expert in statistics (learned from Dr. Deming as I did). Would you like to discredit Dr. Deming as well? Juran also recognized the importance of corporate culture or personality in the whole mix of things. Something I don’t think should be dismissed. Deming wasn’t as good at that, especially in public settings.
Other than that, I couldn’t care less about your opinions
Please then, if you could care less about my opinions, then stop responding to them.  
and your “famous” contributions. …
I have never claimed to be famous, nor have I claimed any of my contributions to be famous. I only know that I am good, and that my techniques are effective.
and “fruitcake”, “idiot”, and your absolutely out of control ranting about “Jack Daniels”
Did you do a control chart on my control regarding ranting about JD? If so, can I see your data that shows it “out of control”? Indeed, I suspect such discussions are more in control in this forum. Though inappropriate, I might agree. And if you read the threads regarding my Jack Daniel’s discussions, I have apologized for that, and I have also apologized for name calling. And I have slipped once in each case since (once with you). But, if do not appreciate being called names (e.g., idiot or fruitcake), then post your own name and stick to it, and stop acting like either (ooops I might have slipped again).
that’s worthy a professional aka “Dr.” aka “consultant” … any other titles you can randomly throw around to make you feel better about yourself?
And as far as my academic education goes, I received my PhD in business with focus on statistics and psychology over a decade ago. I also have a degree in pre-medicine. I also learned personally from Dr. Edwards Deming. I also was a student with (not of) Dr. Don Wheeler. So, just to make you more secure, I am only studying now from experience and the knowledge of others (BTW, I suggest you do the same). Oh, I do not use any aka names as you do. I am always Dr. Scott. Who the heck are you?
As for my contributions, YOU don’t worry have to worry about them. I find it embarrasing
(you again should be ashamed again that you cannot spell embarrassing correctly. I am not saying English is the superior language as you suggested in your previous post. I am only saying if you are going to use it, then use it correctly)
to sign them with “Dr. XYZ” in an environment that is dedicated to professionals who for the most part are still working on their academic education.
You should be embarrassed not to stick to one name, fake or not (which in your case is always fake, never the same).  You should also be embarrassed when you are wrong, but be proud you have learned from your mistake.
Have a good night. You really need one to clear your mind :-))))).
My mind is never clear. I am always studying or working on problems. A clear mind is comatose. Maybe that is what you aspire to be.
P.S. A “Z” is the last letter of the alphabet in capital letter. If you want to know what the formula for a z-value is (population/sample) and how to use it in its various practical applications, please use the google search function. I’m not your statistics mentor.
The z letter is also the last letter of the alphabet in lower case. And no, the formula for Z is Different than what you say. It is (Y1 – Y2)/Sigma (that is the Big sigma using N in the denominator rather than the little one with n-1). And so no, you are not my statistics mentor. Apparently I am yours. God knows you need one.
Regards,
 
Dr. Scott
 

Not so Great,
It is called statistics. Have your ever heard of them or the skills used to identify them?
If not, then you are welcome to take my classes and have me as you Sensei.
Dr. Scott

First – there is a heck of a lot of good stuff here. Serious queries are posted and a number of helpful responses are given. In that regard it serves frequently as a surogate mentor for those who don’t have access to one.
However, to your point, it is also a reflection of human nature. So, yes, there are egos and attitudes…just a sample set of the population.
Have faith and return if you need help with an issue – you will likely get it.

Well there you go Janet…20+ posts to your query and Ape finally gives you a straightforward, comprehendable answer. Not saying others didn’t contribute as well – but the simplicity of the answer impressed me. Thanks Ape.

Darth,Yesterday was my final day with the mother ship. I do not know what I will be doing, but after 7 years, I knew I could no longer continue with the mother ship.Pete aka “He who attempts to stow colleagues in the trunk”

Reading the question again – I agree with Gary that, given your data, your asking for the sigma -score: the number of standards deviations between the process mean and the nearest spec. limit. In your case, your process is operating at level of sigma = 4

Sent a response to wifey’s email but you can contact me at [email protected]
 

Darthmeister,
 
Since you were kind enough to ask and since it roughly coincided with one of my visits to the isixsigma.com homeland, I initially began posting on this site as an outlet from the pedantic and continued for a time because it was a meeting and debating place for highly creative nonlinear thinkers in the business process improvement field.   
 
Then the site had a shift to the more pedantic with fewer riots incited, no great debates planned and more small-minded picking at each other.    Anytime pettiness counts more than mathematics and wit, you’re tracking in the wrong direction (in my gentle and humble opinion) – plus I began to appreciate Stan4’s input so I figured I was in the throes of some severe psyche warping myself.   
 
But it is good to see you back on screen. I hope all’s well and give a buzz next time you’re in Chicago.
 
Vinny, PhD (from a really good school), MBB (from a really successful deployment in advanced medical devices)

you do love to toot your own horn, probably because no one else will give you a blessing. 

Dr. Stevo – I have this pain in my side….could you look at it?

Darth,That wasn’t me. Someone is suffering from Stan envy – must have a
pretty hollow life.

Blessed AH,
You’re blessed, really blessed … Still four questions open:
I am not the one that calls me “blessed” (though I feel I have been). Why you call yourself “Blessed” is a mystery to me and others I am sure. I have yet to see you offer or receive ANY value in this forum.
1. What was Likert’s publication from 1929 that you bragged about the other day?
Please quote by “brag” of the work I only quoted which was developed by a truly talented man. (Still trying to figure out what your claim the name blessed is).
Likert received his PhD in 1932 from Columbia Univeristy (Likert, Rensis (1932): A technique for the measurement of attitudes. Archives of Psychology No. 140.). Dr. R. Likert developed his scale (the Likert Scale) in 1929 and tested it within his dissertation. It has also been used and “somewhat” confirmed by Thurstone (Thurstone, L. L. and E.J. Chave (1929): The measurement of attitudes. Chicago: University of Chicago Press.)
Also refer to the isixsigma post: https://www.isixsigma.com/forum/showmessage.asp?messageID=127101
2. Why do you suggest a test re-test reliability on a survey?
It depends on the nature and form of the survey. But in short, it is not a test re-test that I recommended, but rather a method of replication. Are you familiar with that term? Or are you merely as mere as you appear?
3. And the capitalized Z in one case is a population, in the other the T is a sample? What are you on?
Z or z and T or t represents a population versus samples. What I am on is the correct use of stats to improve processes? What are you on? 
4. You forgot “graduated from one of the top 25 Universities in the US”, Hm, second place is still a loser, and that places you right and square in the middle of the field with now not much expectation for permanent tenure. Maybe, that’s why you’re such a bitter, old, part-time consultant who has to share his limited and now outdated knowledge and his imagined CV so profusely on this site. z and t values, give us a break!
Being a PhD graduate from a top 25 university places my degree in the top .32% of all universities. Oh, and in case you are wondering, I was top 3% in my class. Furthermore, at least I graduated. I bet you wish you had. And I suspect you wish it was from a top 25 school.
Whatever way you turn it. You’re a very sad case. There simply isn’t very much to you other than your self-delusion.
My statements are of fact or opinion! I have previously given you the definition of delusion or delusional, but your memory seems impaired. So here it is again for you; “a: something that is falsely or delusively believed or propagated b: a persistent false psychotic belief regarding the self or persons or objects outside the self that is maintained despite indisputable evidence to the contrary; also : the abnormal state marked by such beliefs.
YOU seem to fit that definition so very well.
As for the first-timer: Don’t bother, this site is a recycling bin of various introductory topics in statistics, with “Dr.” Scott assumming he’s the Dean of the Sesame Street Statistics Faculity on a public forum.
Then why don’t you add to the recycle bin and answer a question yourself now and then, rather than becoming a part of the bin that makes it smell so bad? And please learn how to spell.
And if you feel up to it, challenge me with something not so “simple” (if you can beg a question from someone that knows more than you).
And for one last time; you seem to keep questioning my degree. My PhD is in Business Administration with a supporting area in Psychology. Supporting areas of a PhD are chosen by the candidate and approved by the dissertation committee chairperson and the dissertation committee (sort of like a minor chosen by an undergraduate, except that s/he is free to choose their minor). I chose mine in Psychology, and it was unanimously approved by the committee.
You would know such things if you had any sort of credentials or degree(s). But obviously you do not.
Now please get over it. I have wasted enough time on you.
Though you are not my friend, and I have absolutely no respect for your behavior, I do sincerely wish that you are able to find help to improve yourself and your attitude toward others.
 Take care,
Dr. Scott

I am ashamed to admit that I read through all of this. Does isixsigma ever moderate these forums?