Me too I've been thinking about it for a few days......................im guessing it would be lower. I read somewhere if you increase the sample size the p-value decreases slightly.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
HSC PAPERS >>http://sdrv.ms/H3cL7l
2013 HSC papers >> http://sdrv.ms/H3cOQk
HSC NOTES >> http://sdrv.ms/GXNPyo
PHYSICS MC and ANSWERS >> http://sdrv.ms/H3da9C
PHYSICS CORE OPTIONS HARD TEST (with solutions)>> http://sdrv.ms/GXNTOQ
Sorted HSC Q's >> https://www.mediafire.com/folder/cls...ns_%2B_options
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
My stats knowledge is minimal, but wouldn't it decrease?
I assume that whats going on is you have the hypothesis that the avg sleeping hours of a student are normally distributed with mean 8 and variance V. We are doing a one-tailed test with test statistic our sample mean.
If our p-value is 0.1 that means the observed sample mean m of our initial sample of 20 students is quite a bit less than 8. (So the probability of a randomly selected student from our population sleeping less than m hours on average is only 0.1).
But the distribution of sample means in samples of size n is given by N(8,V/n). So as n increases, the probability of the the test statistic being smaller than m decreases, i.e. the p-value decreases.
Is there some other choice of hypothesis/test statistic here? Without specifying such a choice, the one I have made above seems natural to me.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
The more I think about it the more I think the P-Value actually decreases
Case 1:
Case 2:
So what I can interpret from this is it decreases.
Last edited by davidgoes4wce; 1 Jun 2016 at 5:23 PM.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
Also I will admit , I did not know how to calculate a P-Value manually up until last week. (having studied high school stats+ uni stats for around 6 years) If you guys are looking to get better at statistics with Excel highly recommend this book by : Mark Berenson, David Levine and Kathryn Szabat, BUSS1020 Quantitative Business Analysis.
I personally feel they explain stats better than the Science, Advanced Science, Engineering or Psychology way of statistics.
Last edited by davidgoes4wce; 1 Jun 2016 at 5:22 PM.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
Sure, if you are using the t-test then use that formula instead, it will still decrease. You can compute the p-value in terms of n by using the t-distribution and show it decreases by using calculus or whatever else you like.
Just think about it intuitively, a sample of two students who on average undersleep by H hours is far less significant than a sample of 1,000,000 students who on average undersleep by the same amount. (With both samples having the same s.d.)
The latter is far greater evidence of a trend of undersleeping students, and any reasonable statistical test should reflect this.
Ans : 11.7
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
Expand the square and note that the mean (and also its square) is a constant.
In the second summand there is a common factor which can be factorised out.
In the third summand note that you are summing the same constant value n times.
Here is something more theoretical.
Suppose for j=1,...,n are i.i.d random variables for some unknown parameters .
1. Define
Compute
2. Hence define in terms of a random variable that has expected value and variance . Compute the pdf of this random variable in terms of special functions.
3. What happens as ? Prove this.
(This question outlines some of the theory behind something used several times in this thread.)
Last edited by seanieg89; 2 Jun 2016 at 2:52 PM.
Can you guys stop dropping the big guns... you're making statistics look hard.
Huh? Not all of statistics is just plugging numbers into memorised formulae, where do you think these formulae come from?
As always, you have the option of ignoring any question not to your taste.
In any case, this particular question is easier than most of the mathematical questions posted in these forums.
Yep good stuff, it remains to compute Var(s^2), but what you have done is enough to motivate the later parts of the question so don't worry about that if you don't want to.
Screen Shot 2016-06-04 at 11.14.13 pm.zip
Can someone explain for me please
If I am a conic section, then my e = ∞
Just so we don't have this discussion in the future, my definition of the natural numbers includes 0.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
Im thinking the answer is E ( I don't have the solution on me ) Here is my explanation and thinking.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
Last edited by davidgoes4wce; 5 Jun 2016 at 3:56 PM.
| B Eng (Hons) | IB Mathematics SL | IB Mathematics HL | Australian Cricket | Casual University Statistics Tutor
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks