|
Anyone do statistics? HELP! Confidence Intervals for t Distributions etc
|
View this Thread in Original format
| A.J. |
Hey, i was wondering if anyone could help me out because i am uber-confused atm, its 2am and i have an assignment due in 10 hours that i haven't started.
Question- Determine the critical value of t:
(a) 1 - a = 0.95, n=10
*CLUE* I think this has something to do with reading t tables (NOT Z Tables for Standardised Variables, this is different)
I understand stuff for questions where the population mean is known, but i have no clue about T distributions.
If anyone can help me i would be sooooooo grateful. We have only just started this topic and it has me stumped. All i need to do is know how to do it, you don't have to come up with an answer!
Thanks
:D :D :D :D |
|
|
| Boomer187 |
isn't it .05?
the 1 minus alpha determines it right. |
|
|
| A.J. |
That's the answer when the pop. mean is known.
However, the question i'm doing asks for "the critical value of t" given that "1 - a = 0.95, n=10"
The answer is 2.2622, i know that for sure
It has something to do with "degrees of freedom" (which involves the n) |
|
|
| Boomer187 |
| quote: | Originally posted by A.J.
That's the answer when the pop. mean is known.
However, the question i'm doing asks for "the critical value of t" given that "1 - a = 0.95, n=10"
The answer is 2.2622, i know that for sure
It has something to do with "degrees of freedom" (which involves the n) |
aah, yes.
df = n -1
so if you look on your t table, I am assuming this is two tailed, with a significance of .05 and a df of 9, you get 2.262. |
|
|
| A.J. |
Oh crap! That was so blatantly obvious and i missed it. For some reason i kept thinking of the confidence interval of 95% with the critical value of 97.5 (in the positive side)
Damn! thanks for the help.... |
|
|
| Boomer187 |
i hope I would know it, I am a lab instructor for the stats class here, plus I've taken graduate stats....heh. :wtf:
but t-test suck so I am a lil rusty on them, if ya need mo help post on up. |
|
|
| A.J. |
Cheers dude!
I'm just starting my assignment now. Three Questions -->First one is very basic, it just involves using NORMDIST function in Excel to find Probabilities from Z, and the NORMINV function as well
The second is Expected Value (easy!) but the third Question is tricky....it involves confidence intervals, scatter plots, omitting outliers and all sorts of complicated shiite. |
|
|
| Boomer187 |
| its all simple, try running a moderated multiple regression. or and ancova with 4 covariates. |
|
|
| A.J. |
It isn't really too hard because i was always pretty good at mathematics in high school.
Unfortunately we have to use this stupid American textbook :stongue: :stongue: called "Basic Business Statistics" (Berenson, Levine & Krehbiel) and all the examples have inches and crap in them. It's called the METRIC SYSTEM FFS!!!!!! :haha: :haha: :haha: :haha:
However, if you fall a little behind in this it is very hard to catch up!! |
|
|
| Boomer187 |
wtf is the metric system?
inches are simple they are yay long and there are 12 in a foot.. :P. |
|
|
| Photo_bot_2k1 |
| woot for random ass arbitrary units! |
|
|
| LinX |
| quote: | Originally posted by Photo_bot_2k1
woot for random ass arbitrary units! |
amen to that. |
|
|
|
|
