*** official ap statistics 2013 thread ***

<p>For the find the sample size one, I remember I got b. Don’t remember which number that is. Hope that’s right. I plugged in each one and checked.</p>

<p>how did you get ur test statistic as 2.626</p>

<p>B is too small, it was like 230. It was 350 or 413, but I don’t see how it could be 350 if you are at a 95 percent confidence interval to get an error of 5 or less.</p>

<p>It was 99% confidence. 95% was a different question.</p>

<p>Did we ever get the SD of the egg??
I did
SD of a full carton is equal to the square root of the variance of cardboard plus the SD of the egg squared over 12.</p>

<p>I think went and solved for the standard deviation of the egg by plugging in numbers until I get the too sides equal. It’s like the reverse of adding to SDs.</p>

<p>Was this how you do it or was I WAY off?</p>

<p>Also I thought the test was way too easy… Probably 35/40 MC and almost perfect FR.</p>

<h1>6 was a dissapointment. I was looking forward to something fun and challenging but instead it was stupidly easy. Sigh…</h1>

<p>You use matrices for chi square. My p value was .011, it’s still in my calculator XD</p>

<p>for the frq about stratifying, was the question which method is better to stratify by or under which circumstances is it better to stratify by campus?</p>

<p>There were multiple 95 percent intervals on the test. No matter, I still got 2.626 for the CV.</p>

<p>do you remember how you got 2.626 for the CV?</p>

<p>Off the chart, df of 100. Was it 99 or 95, I don’t have it in front of me…</p>

<p>once again, what i dont undestnad for the chi squared question is if you get a p value of .01 you will reject the null…and that means there is a relation…thats just not true…</p>

<p>lol i think im the only one here who got a different answer for the SD of egg question</p>

<p>The numbers don’t lie, if you can reject there is a relationship.</p>

<p>for the chi squared one i said no relationship by setting the alpha to .01…
for the sample size MC everyone is tlaking about it is 350 (344 actually but not a choice)
and the regression question everyone is talking about i didn’t get the x bar y bar thing i got the r has to stay the same or something lol it doesnt pass through x bar y bar i think it passes through (z of x) bar and (z of y) bar</p>

<p>i remember plugging in the formula and getting 343, so i just rounded it up to 350</p>

<p>2 questions: the frqs are released in 2 days from after the exam or is it 2 weeks? also does anyone remember the order of the frqs or like the basic jist of them and what they got as the answers?</p>

<p>But why is it 350? I swear it was a 95 percent CI. And I was between the r one and x bar one. Probably is the r value is the same.</p>

<p>I got 350 as well. I’m predicting I got around 35/40 on MC and all FR right except for one or two parts. I’m pretty positive I got a 5, that was ridiculously easy.</p>

<p>yeah i agree it was easy lol…
@TheBombingRange: it was 99 percent confidence so m = t(s/root n) just plug em in…
and for the r and x bar one r will not change because there was no transformation on the variables (standardizing to a z score is not a transformation only add,subtract,mult,div)</p>

<p>I put 350 too but I was kinda skeptical because all the other answers had 3 significant digits and 350 was only 2 so I didn’t know why they would randomly round that…</p>

<p>& I put that r stays the same. I made up random data and then found the z-scores of both of them to confirm.</p>