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Forum nameThe Pits v3.1
Topic subjectStatistics Help Needed
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i60&topic_id=21360
21360, Statistics Help Needed
Posted by DanKid, Feb-24-07 06:57 PM
What's up guys. I'm taking a statistics class this semster and I'm really having a hard time understanding this $#!+. Can anyone on here help? I have a take-home assignment that has one problem which is set-up as having ten stores with a breakdown of employees in the stores as being 14,22,24,28,34,41,46,48,51,and 52. I got a mean of 36 by adding and dividing by 10. I got a mode of 0 since none of the numbers repeat. A median of 37.5 but I can't answer the other 6 questions which are the following:

1. What is the standard deviation?
2. What is the coefficient of variation?
3. What is the coefficient of skewness?
4. What is the Z value for the store containing 22 employees?
5. Same question as above but for the store containing 46?
6. Is the info positively or negative skewed?

Thanks in advance guys.
21361, RE: Statistics Help Needed
Posted by cs82685, Feb-24-07 07:28 PM
Originally posted by DanKid
What's up guys. I'm taking a statistics class this semster and I'm really having a hard time understanding this $#!+. Can anyone on here help? I have a take-home assignment that has one problem which is set-up as having ten stores with a breakdown of employees in the stores as being 14,22,24,28,34,41,46,48,51,and 52. I got a mean of 36 by adding and dividing by 10. I got a mode of 0 since none of the numbers repeat. A median of 37.5 but I can't answer the other 6 questions which are the following: 1. What is the standard deviation? 2. What is the coefficient of variation? 3. What is the coefficient of skewness? 4. What is the Z value for the store containing 22 employees? 5. Same question as above but for the store containing 46? 6. Is the info positively or negative skewed? Thanks in advance guys.


I too am in a stat class this semester. I can answer two of these for you, the first one (hint: excel is your friend) and the fourth one. Will update with answers in a few


1. Enter data into excel then use the following equation
=stdev(Range)

=13.5072

4. To convert the data value to the z-value you use the following equation: (y-bar - Mu)/sigma

y-bar is the data you want to convert to the z-score
Mu is the mean (average, in excel =average(Range))
sigma is standard deviation

=(22-36)/13.5072 = -1.03648


^Really this equation is simple but statisticians made it really complicated to understand by using stupid ass symbols. It's just how many standard deviations away from the mean some number is. The mean is equal to zero and each standard deviation is equal to one. In this case the number is 22. Standard deviation of 13.5, so one standard deviation from 36 in either direction is 22.5 and 49.5. How many times does 13.5 go into the difference between the mean and 22. 22-36 = -14. -14/13.5 = -1.03648.
21362, RE: Statistics Help Needed
Posted by DanKid, Feb-25-07 02:12 AM
Originally posted by cs82685
I too am in a stat class this semester. I can answer two of these for you, the first one (hint: excel is your friend) and the fourth one. Will update with answers in a few 1. Enter data into excel then use the following equation =stdev(Range) =13.5072 4. To convert the data value to the z-value you use the following equation: (y-bar - Mu)/sigma y-bar is the data you want to convert to the z-score Mu is the mean (average, in excel =average(Range)) sigma is standard deviation =(22-36)/13.5072 = -1.03648 ^Really this equation is simple but statisticians made it really complicated to understand by using stupid ass symbols. It's just how many standard deviations away from the mean some number is. The mean is equal to zero and each standard deviation is equal to one. In this case the number is 22. Standard deviation of 13.5, so one standard deviation from 36 in either direction is 22.5 and 49.5. How many times does 13.5 go into the difference between the mean and 22. 22-36 = -14. -14/13.5 = -1.03648.


Wow thanks for the response and the excel tip. I will definately start messing around with excel to see if I can get it to work. I'm gonna have to keep reading your response a few times to fully understand the whole concept. The thing that really makes it hard is that the book for this class is very vague. The teacher explains it one way and the book tells you a whole different thing. :scratch
21364, RE: Statistics Help Needed
Posted by ez, Feb-25-07 07:15 AM
and 6) it's negatively skewed (or "left" skewed), because most of the terms are in the 40s-50s, with a few terms farther away in the left tail
21365, RE: Statistics Help Needed
Posted by cs82685, Feb-25-07 07:25 AM
Originally posted by DanKid
Wow thanks for the response and the excel tip. I will definately start messing around with excel to see if I can get it to work. I'm gonna have to keep reading your response a few times to fully understand the whole concept. The thing that really makes it hard is that the book for this class is very vague. The teacher explains it one way and the book tells you a whole different thing. :scratch


Yeah statistics sucks a lot and all them damn symbols make it so confusing trying to remember what each one means.

Didn't see that 5 was the same as 4

so 5) would be (46-36)/13.5 = 10/13.5 = .74074
21367, RE: Statistics Help Needed
Posted by CopperEclipse96, Feb-25-07 07:51 AM
i wasn't looking forward to taking a statistics class to begin with, but after reading this, I'm really not.

thanks guys.
21368, RE: Statistics Help Needed
Posted by DanKid, Feb-25-07 10:13 AM
Originally posted by CopperEclipse96
i wasn't looking forward to taking a statistics class to begin with, but after reading this, I'm really not. thanks guys.


LOL. It's not a fun class. It starts out super easy with discussions on general statistics like how many people are there in the world, how many people are there in certain states, etc. and then BOOM! You just get thrown into all this crazy math and symbols. One guy that sits behind me in class told me the other day this is his second time taking it cause he already failed it before. My advice to you when you take this class is to take as many notes as you can and don't miss any classes. I missed one class two weeks ago cause I had the flu and i'm still lost. :cry
21370, RE: Statistics Help Needed
Posted by burntheblobs, Feb-25-07 11:38 AM
Statistics was my favorite math class ever. I took it once in high school and once in college. You guys are just nuubs.
21372, RE: Statistics Help Needed
Posted by bullettdsm, Feb-25-07 01:37 PM
Funny thing is, I went through college on a double major (math being one of them) and I can't even remember enough to answer your questions. Except the last one. It is positively skewed. I'm absolutely positive that the numbers are skewed.(:-) )

Oops, I better put a smiley in there in case you think I'm serious.
21374, RE: Statistics Help Needed
Posted by DR1665, Feb-25-07 02:52 PM
Originally posted by bullettdsm
Funny thing is, I went through college on a double major (math being one of them) and I can't even remember enough to answer your questions.

Proof that you should find a way to take another math class. :P

Statistics is total bullshit. The worst class I took at DeVry. (And I took it in 7 weeks, too. Fuuuuuuck that.)

So much of it is spent trying to mathematically predict the future. It's bullshit. You'll have questions not only asking you the average number of buyers for something, but if the trend is up or down, and then you have to figure out some more bullshit and graph it to "prove" that you're "sure" this is the correct guess, but you'll then have to do another damn computation to determine how much faith you have in saying you're "sure" you got the right answer.

In other words, like I said, it's matheticians trying to predict the future from past events, then mathematically proving they're right, and then mathematically proving that the odds are good that they are. Then real life kicks in and the nutty nature of people in general sets in and all that time goes right out the window.

Let me put it this way... If you tell your boss, "We advertised once a night on Channel 12 last month and got 300 people to mention the commercial special when they bought. Now, the month before, we advertised on once a day on 101.5FM and got 500 people to mention the commercial special when they bought." If your boss has the means, he's going to do BOTH. If he can't, he's going to do the one which brings in more sales. There's no need to prove trends and... GAH.

I fucking hate statistics. Even more than NASCAR.

Good luck to you in getting through the rigid mindfuck with your sanity and at least a D so you never have to take it again, bro.
21397, RE: Statistics Help Needed
Posted by thedawg, Feb-26-07 08:30 AM
Originally posted by DR1665
it's matheticians trying to predict the future from past events, then mathematically proving they're right, and then mathematically proving that the odds are good that they are.

I work for a company that sells statistics. We make an awful lot of money. My DSMs were all paid for by standard deviations.

Stick with the class. It's one of the few classes that has direct relevance in the real world. If you don't get stats, you'll miss out on a lot in the stock market and Vegas later on in life.

Or... if you just want the answers and a middle management position:
http://home.ubalt.edu/ntsbarsh/Business-stat/otherapplets/Descriptive.htm
21373, RE: Statistics Help Needed
Posted by DanKid, Feb-25-07 02:42 PM
Originally posted by burntheblobs
Statistics was my favorite math class ever. I took it once in high school and once in college. You guys are just nuubs.


If your such a genious then what are the answers to questions 2 and 3? :evilgrin
21375, RE: Statistics Help Needed
Posted by cs82685, Feb-25-07 03:44 PM
Originally posted by DanKid
Originally posted by burntheblobs Statistics was my favorite math class ever. I took it once in high school and once in college. You guys are just nuubs.
If your such a genious then what are the answers to questions 3 and 4? :evilgrin


you mean 2 and 3?

21377, RE: Statistics Help Needed
Posted by DanKid, Feb-25-07 04:11 PM
Originally posted by cs82685
Originally posted by DanKid
Originally posted by burntheblobs Statistics was my favorite math class ever. I took it once in high school and once in college. You guys are just nuubs.
If your such a genious then what are the answers to questions 3 and 4? :evilgrin
you mean 2 and 3?


Thanks for the correction. I meant 2 and 3. And Driggs i'm definately praying for that D so I won't have to take this crap class again. The funny thing is that the professor says he sees all his students as the Z in an equation. It made me think about the matrix when Neo's eyes get F'd up and he starts seeing everything in codes. This professor's head is probably so messed up from this statistics crap that he probably even calculates how many times he's gonna take a shit depending on how many calories he eats.
21378, RE: Statistics Help Needed
Posted by cs82685, Feb-25-07 04:25 PM
Originally posted by DanKid
he probably even calculates how many times he's gonna take a shit depending on how many calories he eats.


LMAO
21382, RE: Statistics Help Needed
Posted by ez, Feb-25-07 06:48 PM
ah you're all a bunch of sissies. Stats is about life, math is describing life. Don't cry about these basic stat classes, b/c it's not like you have to do multivariate analysis in them or anything. There's not even any matrix algebra, and not an eigenvalue or eigenvector to speak of. Most people hate stats - and that's why statisticians make good money
21392, RE: Statistics Help Needed
Posted by bullettdsm, Feb-26-07 07:56 AM
Originally posted by ez
Most people hate stats - and that's why statisticians make good money

See, that's not logical.

Most people hate me and I don't make good money....:shrug

AND I can also predict the future with certainty....there will be another post after this post. Tarmac has spoken
21400, RE: Statistics Help Needed
Posted by vegasdsmr, Feb-26-07 11:48 AM
my stats professor at UNLV could hardly speak english.....

try learning that shit from only a book (w/no understandable help from a professor)...

Dr. Tan was his name... think he was from cambodia or some 3rd world country....
21401, RE: Statistics Help Needed
Posted by SonicYan, Feb-26-07 01:49 PM
Biostatistics was easy...

Easy A right there... :bowdown:

I think its the only math class I could get an A in, plus basic calculus. :P

I don't remember anything tho... :P