p-values on real dat?

[duke2121]

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Took qvault math test 3, had a really complicated p-value problem. It is #11 on that test. Are we supposed to know how to do that in depth of a calculation for a p-value? I hope its more conceptual, because I understand at least that part.

 

[Member 8586]

Took qvault math test 3, had a really complicated p-value problem. It is #11 on that test. Are we supposed to know how to do that in depth of a calculation for a p-value? I hope its more conceptual, because I understand at least that part.

i saw that explanation and honestly just skipped it after trying to understand that long explanation and since im close to the test date...BUT someone who just took the test said he had two of those in his QR section (look at the recent breakdown threads) so idk, maybe i should figure it out....i have no idea what it is....feel like explaining at all? lol

 

[duke2121]

i saw that explanation and honestly just skipped it after trying to understand that long explanation and since im close to the test date...BUT someone who just took the test said he had two of those in his QR section (look at the recent breakdown threads) so idk, maybe i should figure it out....i have no idea what it is....feel like explaining at all? lol

All I know is that if p<5% you reject the null hypothesis and the observation is statistically significant. If p value is >5% observation is not considered significant. As far as calculating p-values, dear god I hope we don't have to do that.

 

[Electrophilic]

From what I remember, a p-value is used in stats to describe the probability of something happening purely by chance. Different tests have different cut offs for what is considered statistically significant. If that doesn't help theres always

http://en.wikipedia.org/wiki/P_value

 

[TheDentist16]

All I know is that if p<5% you reject the null hypothesis and the observation is statistically significant. If p value is >5% observation is not considered significant. As far as calculating p-values, dear god I hope we don't have to do that.

As far as my experience with the QR section of the real DAT is concerned, I didn't have any really difficult statistics problems dealing with p-values. However, if you do have to know things of p-values, then I would remember the rules as you have already stated regarding null hypotheses and such. I feel that the QR section is more of testing your speed at math rather than testing it in-depth. If I remember correctly, I had a lot of mean/median/mode type of problems in relation to statistics, with a few probability problems as well.

 

[NewBee12]

Duke2121's explanation is good enough. If you have math destroyer I believe test 12 has a few p-value problems. Didn't get any on my test

 

[kies89]

All I know is that if p<5% you reject the null hypothesis and the observation is statistically significant. If p value is >5% observation is not considered significant. As far as calculating p-values, dear god I hope we don't have to do that.

i had 2 p-value and one other statistical problem on my test...(i didnt really study cuz i didnt expect any)

i knew what duke2121 explained but that wasnt enough to get the quesiton right..
make sure you fully understand p-value and do some practice questions

 

[duke2121]

So I looked at the following link for an explanation, specifically the coin flip example. http://en.wikipedia.org/wiki/P-value
I tried using this method for the question on qVault math test #2. It didn't work. Can anyone help?

 

[Member 8586]

All I know is that if p<5% you reject the null hypothesis and the observation is statistically significant. If p value is >5% observation is not considered significant. As far as calculating p-values, dear god I hope we don't have to do that.

thanks ima just go with this and hope no calculation of p values is on there lol

 

[Member 8586]

i had 2 p-value and one other statistical problem on my test...(i didnt really study cuz i didnt expect any)

i knew what duke2121 explained but that wasnt enough to get the quesiton right..
make sure you fully understand p-value and do some practice questions

ah krap..maybe ill have to figure it out...if i have some extra time between cramming, ill have to dig into this 🙁

 

[ktran17]

Since we're on the topic of p-values, It's also important to remember, when you use the "=ttest" function on excel, it actually gives you p-value and not tcalc. Therefore, if you ever have to compare tcalc vs ttable, you simply can't just type in function "=ttest". You would have to use the the statistical data analysis plugin in order to find tstat which is equivalent to tcalc.

This took me a good hour to realize and frustrated me when I was taking my quantitative chemistry lab =P..